Chapter 15
I-(1)

Three people sat eating breakfast in the kitchen.
Outside, the sun shone. It was a lovely day. The storm was a thing of the past.
And with the change in the weather, a change had come in the mood of the prisoners on the island.
They felt now like people just awaking from a nightmare.
There was danger, yet, but it was danger in daylight. That paralyzing atomosphere of fear that had wrapped them round like a blanket yesterday while the wind howled outside was gone.
Lombard said:
“We’ll try heliographing today with a mirror from the higher point of the island. Some bright lad wandering on the cliff will recognize SOS when he sees it, I hope. In the evening we could try a bonfire - only there isn’t much wood - and anyway they might just think it was song and dance and merriment.”
Vera said:
“Surely someone can read Morse. And then they’ll come to take us off. Long before this evening.”
Lombard said:
“The weather’s cleared all right, but the sea hasn’t gone down yet. Terrific swell on! They won’t be able to get a boat near the island before tomorrow.”
Vera cried:
“Another night in this place!”
Lombard shrugged his shoulders.
“May as well face it! Twenty-four hours will do it, I think. If we can last out that, we’ll be all right.”
Blore cleared his throat. He said:
“We’d better come to a clear understanding. What’s happened to Armstrong?”
Lombard said:
“Well, we’ve got one piece of evidence. Only three little soldier boys left on the dinner table. It looks as though Armstrong had got his quietus.”
Vera said:
“Then why haven’t you found his dead body?”
Blore said:
“Exactly.”
Lombard shook his head. He said:
“It’s damned odd - no getting over it.”
Blore said doubtfully:
“It might have been thrown into the sea.”
Lombard said sharply:
“By whom? You? Me? You saw him go out of the front door. You come along and find me in my room. We go out and search together. When the devil had I time to kill him and carry his body round the island?”
Blore said:
“I don’t know. But I do know one thing.”
Blore said:
“The revolver. It was your revolver. It’s in your possession now. There’s nothing to show that it hasn’t been in your possession all along.”
“Come now, Blore, we were all searched.”
“Yes, you’d hidden it away before that happened. Afterwards you just took it back again.”
“My good blockhead, I swear to you that it was put back in my drawer. Greatest surprise I ever had in my life when I found it there.”
Blore said:
“You ask us to believe a thing like that! Why the devil should Armstrong, or anyone else for that matter, put it back?”
Lombard raised his shoulders hopelessly.
“I haven’t the least idea. It’s just crazy. The last thing one would expect. There seems no point in it.”
Blore agreed.
“No, there isn’t. You might have thought of a better story.”
“Rather proof that I’m telling the truth, isn’t it?”
“I don’t look at it that way.”
Philip said:
“You wouldn’t.”


注釈：
Three people sat eating breakfast in the kitchen.
この文は従来の「５文型」理論では説明が難しいですが、「ＳＶＯＣ」文型の自動詞版と考えて下さい。即ち「Three people sat」という文と「Three people were eating breakfast」という文を１つの文にしたものです。日本語では「食べながら座っていた」。

Outside, the sun shone. It was a lovely day. The storm was a thing of the past.
And with the change in the weather, a change had come in the mood of the prisoners on the island.
They felt now like people just awaking from a nightmare.
There was danger, yet, but it was danger in daylight.
That paralyzing atomosphere of fear that had wrapped them round like a blanket yesterday while the wind howled outside was gone.
「That paralyzing atomosphere of fear that had wrapped them round like a blanket yesterday while the wind howled outside」が主語。書き言葉ですから分かりますが、これを口語で言ったら通じない恐れ十分です。「paralyzing」は「人を立ちすくませる」。「howl」はここでは「ヒューヒューうなる」。

Lombard said:
“We’ll try heliographing today with a mirror from the higher point of the island.
「heliograph」はここでは「日光反射信号機で会図する」。

Some bright lad wandering on the cliff will recognize SOS when he sees it, I hope.
「lad」はここでは「やつ」

In the evening we could try a bonfire - only there isn’t much wood - and anyway they might just think it was song and dance and merriment.”
「bonfire」は「大かがり火」。「only」はここでは「残念ながら、あいにく」の意。「merriment」は「陽気なにぎわい（fun）」。

Vera said:
“Surely someone can read Morse. And then they’ll come to take us off. Long before this evening.”
「surely」はここでは「きっと」。「take … off」は「・・・を全体（ここでは島）から取り去る」イメージですのでここでは「連れて行く」。

Lombard said:
“The weather’s cleared all right, but the sea hasn’t gone down yet.
「all right」はここでは副詞で「申し分なく」。「go down」はここでは「おさまる」。

Terrific swell on!
「terrific」はここでは「very great」。「swell」はここでは「波のうねり（surge, wave, roll）」。「on」はここでは副詞で「続いている」の意。

They won’t be able to get a boat near the island before tomorrow.”
Vera cried:
“Another night in this place!”
Lombard shruged his shoulders.
「shrug」は「をすくめる」。

“May as well face it!
「may as well do」は辞書には「（・・・するくらいなら）・・・したがよろしい」と出ています。「・・・するくらいなら」の部分が省略されています。これを補うなら、この文は「I may as well face it as not face it」となります。「もう一晩ここで過ごさないのと同じ位、過ごすのもよい」位のニュアンスです。「もう一晩ここで過すのも悪くない」。

Twenty-four hours will do it, I think.
「do it」には「功を奏する、セックスする、排尿・排便する」の意があります。ここでは最初の意。

If we can last out that, we’ll be all right.”
「last out」は「（ある期間）を生き抜く」。「もし２４時間生き抜くことができれば、我々は大丈夫だろう」。

Blore cleared his throat.
「咳払いした」。

He said:
“We’d better come to a clear understanding. What’s happened to Armstrong?”
Lombard said:
“Well, we’ve got one piece of evidence. Only three little soldier boys left on the dinner table.
It looks as though Armstrong had got his quietus.”
「quietus」は「最後の一撃」。「死んだように見える」。

Vera said:
“Then why haven’t you found his dead body?”
Blore said:
“Exactly.”
「おっしゃる通りだ」。

Lombard shook his head. He said:
“It’s damned odd - no getting over it.”
「本当に奇妙だー理解できない」。

Blore said doubtfully:
“It might have been thrown into the sea.”
Lombard said sharply:
「厳しい口調で言った」。

“By whom? You? Me? You saw him go out of the front door.
You come along and find me in my room. We go out and search together.
過去のことを、現在形を使って表現しています。新聞の見出しとか脚本に使われる手法です。

When the devil had I time to kill him and carry his body round the island?”
Blore said:
“I don’t know. But I do know one thing.”
Blore said:
“The revolver. It was your revolver. It’s in your possession now. There’s nothing to show that it hasn’t been in your possession all along.”
“Come now, Blore, we were all searched.”
「come now」はここでは「非難」を表しています。「これこれ」。

“Yes, you’d hidden it away before that happened. Afterwards you just took it back again.”
“My good blockhead, I swear to you that it was put back in my drawer.
「blockhead」は「でくのぼう」。

Greatest surprise I ever had in my life when I found it there.”
Blore said:
“You ask us to believe a thing like that! Why the devil should Armstrong, or anyone else for that matter, put it back?”
Lombard raised his shoulders hopelessly.
“I haven’t the least idea. It’s just crazy. The last thing one would expect. There seems no point in it.”
Blore agreed.
“No, there isn’t. You might have thought of a better story.”
“Rather proof that I’m telling the truth, isn’t it?”
“I don’t look at it that way.”
Philip said:
“You wouldn’t.”
「You wouldn’t look at it that way.」の省略。「would」は「will」の過去形。“I don’t look at it that way.”と現在形で言っていることに対して過去形で応えています。色々な解釈が可能ですが「お前なら、そのように見ないだろう」⇒「そうだろうな」と訳しておきます。

Chapter 14
VII

Vera cried:
“What?”
Lombard said:
“Vanished clean off the island.”
Blore concurred:
“Vanished - that’s the word! Like some damned conjuring trick.”
Vera said impatiently:
“Nonsense! He’s hiding somewhere!”
Blore said:
“No, he isn’t!
I tell you, there’s nowhere to hide on this island. It’s as bare as your hand! There’s moonlight outside. As clear as day it is. And he’s not to be found.”
Vera said:
“He doubled back to the house.”
Blore said:
“We thought of that. We’ve searched the house, too. You must have heard us. He’s not here, I tell you. He’s gone - clean vanished, vamoosed …”
Vera said incredulously:
“I don’t believe it.”
Lombard said:
“It’s true, my dear.”
He paused and then said:
“There’s one other little fact. A pane in the dining room window has been smashed - and there are only three little soldier boy on the table.”


注釈：
Vera cried:
“What?”
Lombard said:
“Vanished clean off the island.”
「島からすっかり消えてなくなった」。

Blore concurred:
「concur」はここでは伝達動詞で「・・・と言って同意する」の意。

“Vanished - that’s the word! Like some damned conjuring trick.”
「conjure trick」は「魔法をかける」。

Vera said impatiently:
“Nonsense! He’s hiding somewhere!”
Blore said:
“No, he isn’t!
I tell you, there’s nowhere to hide on this island.
「I tell you」は「本当に」。場所を表す場合「island」には「in」ではなく「on」です。

It’s as bare as your hand!
「bare」はここでは「むき出しの（naked）」。

There’s moonlight outside. As clear as day it is. And he’s not to be found.”
Vera said:
“He doubled back to the house.”
「double」はここでは「後戻りする」。

Blore said:
“We thought of that. We’ve searched the house, too. You must have heard us. He’s not here, I tell you. He’s gone - clean vanished, vamoosed …”
「vamoose」は「姿をくらます」。

Vera said incredulously:
「incredulously」は「疑うように」。

“I don’t believe it.”
Lombard said:
“It’s true, my dear.”
He paused and then said:
“There’s one other little fact.
A pane in the dining room window has been smashed - and there are only three little soldier boy on the table.”
「pane」は「窓ガラス」。

Chapter 14
VI

Vera, left to wait results, got up and dressed.
She glanced over once or twice at the door. It was a good solid door. It was both bolted and locked and had an oak chair wedged under the handle.
It could not be broken open by force. Certainly not by Dr. Armstrong. He was not a physically powerful man.
If she were Armstrong intent on murder, it was cunning that she would employ, not force.
She amused herself by reflecting on the means he might employ.
He might, as Philip had suggested, announce that one of the other two was dead. Or he might possibly pretend to be mortally wounded himself, might drag himself groaning to the door.
There were other possibilities. He might inform her that the house was on fire. More, he might actually set the house on fire … Yes, that would be a possibility. Lure the other two men out of the house, then, having previously laid a trail of petrol, he might set light to it. And she, like an idiot, would remain barricaded in her room until it was too late.
She crossed over to the window. Not too bad. At a pinch one could escape that way. It would mean a drop - but there was a handy flower bed.
She sat down and picking up her diary began to write in it in a clear flowing hand.
One must pass the time.
Suddenly she stiffened to attention. She had heard a sound. It was, she thought, a sound like breaking glass. And it came from somewhere downstairs.
She listened hard, but the sound was not repeated.
She heard, or thought she heard, stealthy sounds of footsteps, the creak of stairs, the rustle of garments - but there was nothing definite and she concluded, as Blore had done earlier, that such sounds had their origin in her own imagination.
But presently she heard sounds of a more concrete nature. People moving about downstairs - the murmur of voices. Then the very decided sound of someone mounting the stairs - doors opening and shutting - feet going up to the attics overhead. More noises from there.
Finally the steps came along the passage. Lombard’s voice said:
“Vera. You all right?”
“Yes. What happened?”
Blore’s voice said:
“Will you let us in?”
Vera went to the door. She removed the chair, unlocked the door and slid back the bolt. She opened the door. The two men were breazing hard, their feet and the bottom of their trousers were soaking wet.
She said again:
“What’s happened?”
Lombard said:
“Armstrong’s disappeared …”


注釈：
Vera, left to wait results, got up and dressed.
She glanced over once or twice at the door. It was a good solid door.
It was both bolted and locked and had an oak chair wedged under the handle.
「wedge」はここでは「を押しこむ（squeeze）」。

It could not be broken open by force. Certainly not by Dr. Armstrong. He was not a physically powerful man.
If she were Armstrong intent on murder, it was cunning that she would employ, not force.
「intent on murder」は「殺人を意図している」（Armstrongを修飾）。「cunning」は「狡猾さ（shrewdness）」。

She amused herself by reflecting on the means he might employ.
「reflect on …」で「・・・を熟考する」。

He might, as Philip had suggested, announce that one of the other two was dead.
Or he might possibly pretend to be mortally wounded himself, might drag himself groaning to the door.
「mortally」はここでは「ひどく」。「groan」は「うめく（moan, cry, call out）」。

There were other possibilities. He might inform her that the house was on fire. More, he might actually set the house on fire … Yes, that would be a possibility. Lure the other two men out of the house, then, having previously laid a trail of petrol, he might set light to it. And she, like an idiot, would remain barricaded in her room until it was too late.
She crossed over to the window. Not too bad. At a pinch one could escape that way. It would mean a drop - but there was a handy flower bed.
「handy」はここでは「手ごろな（useful, convenient, helpful, functional）」。

She sat down and picking up her diary began to write in it in a clear flowing hand.
「flowing hand」は「流れるような書体」。

One must pass the time.
「pass the time」は「時間をつぶす」。

Suddenly she stiffened to attention.
「stiffen」はここでは「堅くなる（become stiff）」。「attention」はここでは「気をつけの姿勢」。「突然、直立不動の姿勢になった」。

She had heard a sound. It was, she thought, a sound like breaking glass. And it came from somewhere downstairs.
She listened hard, but the sound was not repeated.
She heard, or thought she heard, stealthy sounds of footsteps, the creak of stairs, the rustle of garments - but there was nothing definite and she concluded, as Blore had done earlier, that such sounds had their origin in her own imagination.
「stealthy」は「quiet and secret」。「footstep」はここでは「歩み」。「creak」はここでは「ギーギー鳴る音」。「the rustle of garments」は「きぬずれの音」。「conclude」はここでは「・・・と結論を下す（judge, decide）」。

But presently she heard sounds of a more concrete nature.
「presently」はここでは「やがて（soon, shortly）」。

People moving about downstairs - the murmur of voices. Then the very decided sound of someone mounting the stairs - doors opening and shutting - feet going up to the attics overhead. More noises from there.
「murmur」はここでは「（はっきりしない連続的な）かすかな音」。「decided」は「明確な（distinct, clear）」。「attic」は「屋根裏部屋」。

Finally the steps came along the passage. Lombard’s voice said:
“Vera. You all right?”
“Yes. What happened?”
Blore’s voice said:
“Will you let us in?”
Vera went to the door. She removed the chair, unlocked the door and slid back the bolt. She opened the door. The two men were breazing hard, their feet and the bottom of their trousers were soaking wet.
「soaking wet」は「びしょびしょに濡れていた」。

She said again:
“What’s happened?”
Lombard said:
“Armstrong’s disappeared …”

Chapter 14
V-(4)

Blore went swiftly back along the corridor.
He paused first at Dr. Armstrong’s door and tapped. There was no answer.
He waited a minute, then went on to to Philip Lombard’s room.
Here the answer came at once.
“Who’s there?”
“It’s Blore. I don’t think Armstrong is in his room. Wait a minute.”
He went on to the door at the end of the corridor. Here he tapped again.
“Miss Claythorne. Miss Claythorne.”
“Who is it? What’s the matter?”
“It’s all right, Miss Claythorne. Wait a minute. I’ll come back.”
He raced back to Lombard’s room. The door opened as he did so. Lombard stood there. He held a candle in his left hand. He had pulled on his trousers over his pyjama jacket. He said sharply:
“What the hell’s all this?”
Blore explained rapidly. Lombard’s eyes lit up.
“Armstrong - eh? So he’s our pigeon!” He moved along to Armstrong’s door. “Sorry, Blore, but I don’t take anything on trust.”
He rapped sharply on the panel.
“Armstrong - Armstrong.”
There was no answer.
Lombard dropped to his knees and peered through the keyhole. He inserted his little finger gingerly into the lock.
He said:
“Key’s not in the door on the inside.”
Blore said:
“That means he locked it on the outside and took it with him.”
Philip nodded:
“Ordinary precaution to take. We’ll get him, Blore … This time, we’ll get him! Half a second.”
He raced along to Vera’s room.
“Vera.”
“Yes.”
“We’re hunting Armstrong. He’s out of his room. Whatever you do, don’t open your door. Understand?”
“Yes, I understand.”
“If Armstrong comes along and says that I’ve been killed, or Blore’s been killed, pay no attention. See? Only open your door if both Blore and I speak to you. Got that?”
Vera said:
“Yes. I’m not a complete fool.”
Lombard said:
“Good.”
He joined Blore. He said:
“And now - after him! The hunt’s up!”
Blore said:
“We’d better be careful. He’s got a revolver, remember.”
Philip Lombard racing down the stairs chuckled.
He said:
“That’s where you’re wrong.” He undid the front door, remarking, “Latch pushed back - so he could get in again easily.”
He went on:
“I’ve got that revolver!” He took it half out of his pocket as he spoke. “Found it put back in my drawer tonight.”
Blore stopped dead on the doorstep. His face changed.
Philip Lombard saw it.
He said impatiently:
“Don’t be a damned fool, Blore!” I’m not going to shoot you! Go bak and barricade yourself in if you like! I’m off after Armstrong.”
He started off into the moonlight. Blore, after a minute’s hesitation, followed him.
He thought to himself:
“I suppose I’m asking for it. After all -"
After all he had tackled criminals armed with revolvers before now. Whatever else he lacked, Blore did not lack courage. Show him the danger and he would tackle it pluckily. He was not afraid of danger in the open, only of danger undefined and tinged with the supernatural.


注釈：
Blore went swiftly back along the corridor.
He paused first at Dr. Armstrong’s door and tapped. There was no answer.
He waited a minute, then went on to to Philip Lombard’s room.
Here the answer came at once.
“Who’s there?”
“It’s Blore. I don’t think Armstrong is in his room. Wait a minute.”
He went on to the door at the end of the corridor. Here he tapped again.
“Miss Claythorne. Miss Claythorne.”
“Who is it? What’s the matter?”
“It’s all right, Miss Claythorne. Wait a minute. I’ll come back.”
He raced back to Lombard’s room.
「race back」はここでは「走って戻る」。

The door opened as he did so. Lombard stood there. He held a candle in his left hand. He had pulled on his trousers over his pyjama jacket.
「pull on」は「を引っ張るようにして身につける」。

He said sharply:
「sharply」はここでは「とげとげしい口調で」位のニュアンスです。

“What the hell’s all this?”
文の骨格は「What is this?」で「the hell」も「all」も「強調」するために使われています。

Blore explained rapidly.
Lombard’s eyes lit up.
「lit up」は「輝いた」。

“Armstrong - eh? So he’s our pigeon!”
射撃練習の標的のことを「clay pigeon」といいますので、pigeonはここでは「標的」の意で使われているものと思います。彼は拳銃も持っています。

He moved along to Armstrong’s door. “Sorry, Blore, but I don’t take anything on trust.”
He rapped sharply on the panel.
「（彼は）羽目板をドンドンと叩いた」

“Armstrong - Armstrong.”
There was no answer.
Lombard dropped to his knees and peered through the keyhole.
「dropped to his knees」で「ひざをついた」。「peer」は「じっと見る（look closely, narrow one’s eyes）」。

He inserted his little finger gingerly into the lock.
「gingerly」は「非常に慎重に」。

He said:
“Key’s not in the door on the inside.”
Blore said:
“That means he locked it on the outside and took it with him.”
Philip nodded:
“Ordinary precaution to take. We’ll get him, Blore … This time, we’ll get him! Half a second.”
「precaution」は「警戒、用心（safegurad）」。「half a second」は「短い時間」を表します。

He raced along to Vera’s room.
“Vera.”
“Yes.”
“We’re hunting Armstrong. He’s out of his room. Whatever you do, don’t open your door. Understand?”
“Yes, I understand.”
“If Armstrong comes along and says that I’ve been killed, or Blore’s been killed, pay no attention. See? Only open your door if both Blore and I speak to you. Got that?”
「Got that?」は「分かったか？」。

Vera said:
“Yes. I’m not a complete fool.”
Lombard said:
“Good.”
He joined Blore. He said:
“And now - after him!
The hunt’s up!”
「捜索開始」。

Blore said:
“We’d better be careful. He’s got a revolver, remember.”
Philip Lombard racing down the stairs chuckled.
「chuckle」は「くすくす笑う」。

He said:
“That’s where you’re wrong.”
He undid the front door, remarking, “Latch pushed back - so he could get in again easily.”
「undo」はここでは「開く」。「latch」は「掛け金」。

He went on:
“I’ve got that revolver!” He took it half out of his pocket as he spoke. “Found it put back in my drawer tonight.”
Blore stopped dead on the doorstep.
「stopped dead」は「急に立ち止まった」。「doorstep」は「戸口の上がり段」。

His face changed.
Philip Lombard saw it.
He said impatiently:
“Don’t be a damned fool, Blore!” I’m not going to shoot you! Go bak and barricade yourself in if you like!
I’m off after Armstrong.”
「Armstrongを探して出発だ」。

He started off into the moonlight. Blore, after a minute’s hesitation, followed him.
He thought to himself:
“I suppose I’m asking for it. After all -"
「after all」はここでは「（なんのかんのといっても）やっぱり」の意。

After all he had tackled criminals armed with revolvers before now. Whatever else he lacked, Blore did not lack courage.
Show him the danger and he would tackle it pluckily.
「pluckily」は「大胆に」。

He was not afraid of danger in the open, only of danger undefined and tinged with the supernatural.
「in the open」は「公然となっている」。「undefined」はここでは「漠然とした（unspecified, unexplained, vague）」。「tinged with …」は「・・・が入り混じった」。

Chapter 14
V-(3)

Someone creeping about stealthily in the night.
He listened - but the sound was not repeated.
And now a new temptation assailed him. He wanted, desperately, to go out and investigate. If he could only see who it was prowling about in the darlness.
But to open his door would be the action of a fool. Very likely that was exactly what the other was waiting for. He might even have meant Blore to hear what he had heard, counting on him coming out to investigate.
Bloor stood rigid - listening. He could hear sounds everywhere now, cracks, rustles, mysterious whispers - but his dogged realistic brain knew them for what they were - the creation of his own heated imagination.
And then suddenly he heard something that was not imagination. Footsteps, very soft, very cautious, but plainly audible to a man listening with all his ears as Blore was listening.
They came softly along the corridor (both Lombard’s and Armstrong’s rooms were father from the stairhead than his). They passed his door without hesitating or faltering.
And as they did so, Blore made up his mind.
He meant to see who it was! The footsteps had definitely passed his door going to the stairs. Where was the man going?
When Blore acted, he acted quickly, surprisingly so for a man who looked so heavy and slow. He tiptoed back to the bed, slipped matches into his pocket, detached the plug of the electlic lamp by his bed and picked it up, winding the flex round it. It was a chromium affair with a hwavy ebonite base - a useful weapon.
He sprinted noiselessly across the room, removed the chair from under the door handle and with precaution unlocked and unbolted the door. He stepped out into the corridor. There was a faint sound in the hall below. Blore ran noiselessly in his stockinged feet to the head of the stairs.
At that moment he realized why it was he had heard all these sounds so clearly. The wind had died down completely and the sky must have cleared. There was faint moonlight coming in through the landing window and it illuminated the hall below.
Blore had an instantaneous glimpse of a figure just passing out through the front door.
In the act of running down the stairs in pursuit, he paused.
Once again, he had nearly made a fool of himself! This was a trap, perhaps, to lure him out of the house!
But what the other man didn’t realize was that he had made a mistake, had delivered himself nearly into Blore’s hands.
For, of the three tenanted room upstairs, one must now be empty. All that had to be done was to ascertain which!


注釈：
Someone creeping about stealthily in the night.
「creep」には「はう」の他「忍び足で歩く（tiptoe）」の意もあります。「stealthily」は「こっそりと、ひそかに」。「夜に」は通例「at night」が対応しますが「時間の幅が感じられる場合」には「in the night」。

He listened - but the sound was not repeated.
And now a new temptation assailed him.
「temptation」は「衝動（desire, urge, itch, impulse）」。「assail」はここでは「襲撃する（attack）」。

He wanted, desperately, to go out and investigate.
「desperately」はここでは「very much」。「investigate」は「enquire into, look into, go into, prove, explore, scrutinize, inspect」。

If he could only see who it was prowling about in the darlness.
「If he could only see who it was」は「それがだれであるかさえ分かれば（よいのだが）」。「prowl」は「こそこそうろつく（move stealthily）」。

But to open his door would be the action of a fool. Very likely that was exactly what the other was waiting for.
He might even have meant Blore to hear what he had heard, counting on him coming out to investigate.
「have meant Blore to …」は「Bloreに・・・させるつもりであった」

Bloor stood rigid - listening.
「rigid」はここでは「動かない（still）」。

He could hear sounds everywhere now, cracks, rustles, mysterious whispers - but his dogged realistic brain knew them for what they were - the creation of his own heated imagination.
「crack」は「鋭い音（ドカン、バリバリ、ズドン、パチャ、ピシャ、パンパン、ガラガラ）、ポキン、パシャ、ピシャ等）」。「rustle」は「カサカサという音」。「dogged」は「容易に屈しない（tenacious）」。

And then suddenly he heard something that was not imagination. Footsteps, very soft, very cautious, but plainly audible to a man listening with all his ears as Blore was listening.
They came softly along the corridor (both Lombard’s and Armstrong’s rooms were father from the stairhead than his).
「stairhead」は「階段の上りつめたところ」。

They passed his door without hesitating or faltering.
「falter」は「（勇気がないため）ためらう（hesitate）」。

And as they did so, Blore made up his mind.
He meant to see who it was!
「彼は本気でそれが誰かを見るつもりりだった」。

The footsteps had definitely passed his door going to the stairs. Where was the man going?
When Blore acted, he acted quickly, surprisingly so for a man who looked so heavy and slow.
He tiptoed back to the bed, slipped matches into his pocket, detached the plug of the electlic lamp by his bed and picked it up, winding the flex round it.
「detach」は「を取り外す（unfasten, disconnect）」。「flex」は「電気のコード（wire）」。

It was a chromium affair with a hwavy ebonite base - a useful weapon.
「a chromium affair」は「クロム製品」。クロムは硬質の金属、エボナイトは硬質のゴム。

He sprinted noiselessly across the room, removed the chair from under the door handle and with precaution unlocked and unbolted the door.
「sprint」は「（短距離を）全力で走る」。「precaution」は「用心、警戒（caution, care）」


He stepped out into the corridor. There was a faint sound in the hall below.
「hall」はここでは「玄関の広間」。米では「廊下」を意味することもあります。

Blore ran noiselessly in his stockinged feet to the head of the stairs.
「stockinged」は「靴下をはいた」。

At that moment he realized why it was he had heard all these sounds so clearly.
「was」の後に「that」が省略されていると考えると分かり易いです（「it … that」構文）。

The wind had died down completely and the sky must have cleared.
There was faint moonlight coming in through the landing window and it illuminated the hall below.
「landing」は「踊り場」

Blore had an instantaneous glimpse of a figure just passing out through the front door.
「instantaneous」は「瞬間の（immediate, instant, on-the-spot）」。「glimpse」は「ちらりと見えること（brief look, quick look, glance）」。「figure」は「（輪郭で分かる）人の姿（silhouette）」。

In the act of running down the stairs in pursuit, he paused.
Once again, he had nearly made a fool of himself!
「make a fool (out) of oneself」は「ばかなことをして物笑いになる」の意の成句。

This was a trap, perhaps, to lure him out of the house!
「lure」はここでは「をおびき出す」。

But what the other man didn’t realize was that he had made a mistake, had delivered himself nearly into Blore’s hands.
For, of the three tenanted room upstairs, one must now be empty.
All that had to be done was to ascertain which!
「ascertain」は「を確かめる（find out, discover）」。