“It is capable of sixty miles an hour,” Granet declared.

“Perhaps I may spare you the trouble,” Thomson proceeded drily, “of further explanations, Captain Granet, when I tell you that your car was observed by one of the sentries quite a quarter of an hour before the arrival of the Zeppelins and the lighting of that flare.  Your statements, to put it mildly, are irreconcilable with the facts of the case.  I must ask you once more if you have any other explanation to give as to your movements last night?”

“What other explanation can I give?” Granet asked, his brain working fiercely.  “I have told you the truth.  What more can I say?”

“You have told me,” Major Thomson went on, and his voice seemed like the voice of fate, “that you arrived here in hot haste simultaneously with the lighting of that flare and the dropping of the bombs.  Not only one of the sentries on guard here, but two other people have given evidence that your car was out there in the lane for at least a quarter of an hour previous to the happenings of which I have just spoken.  For the last time, Captain Granet, I must ask you whether you wish to amend your explanation?”

There was a little movement at the further end of the room.  A curtain was drawn back and Isabel Worth came slowly towards them.  She stood there, the curtains on either side of her, ghastly pale, her hands clasped in front of her, twitching nervously.

“I am very sorry,” she said.  “This is all my fault.”

They stared at her in amazement.  Only Granet, with an effort, kept his face expressionless.  Sir Meyville began to mutter to himself.

“God bless my soul!” he mumbled.  “Isabel, what do you want, girl?  Can’t you see that we are engaged?”

She took no notice of him.  She turned appealingly towards Major Thomson.

“Can you send the soldiers away for a moment?” she begged.  “I don’t think that they will be needed.”

Major Thomson gave a brief order and the men left the room.  Isabel came a little nearer to the table.  She avoided looking at Granet.

“I am very sorry indeed,” she went on, “if anything I have done has caused all this trouble.  Captain Granet came down here partly to play golf, partly at my invitation.  He was here yesterday afternoon, as my father knows.  Before he left—­I asked him to come over last night.”

There was a breathless silence.  Isabel was standing at the end of the table, her fingers still clasped nervously together, a spot of intense colour in her cheeks.  She kept her eyes turned sedulously away from Granet.  Sir Meyville gripped her by the shoulder.

“What do you mean, girl?” he demanded harshly.  “What do you mean by all this rubbish?  Speak out.”

Granet looked up for a moment.

“Don’t,” he begged.  “I can clear myself, Miss Worth, if any one is mad enough to have suspicions about me.  I should never—­”