“It was a mistake for which you could scarcely hold me responsible,” Granet protested, “and you must really excuse me if I fail to see the connection.  Perhaps you will tell me, Major Thomson, what I am here for?”

Major Thomson seated himself before the desk and leaned a little back in his chair.

“We sent for you,” he said, “because we are looking for two men who lit the magnesium light which directed the Zeppelin last night to this locality.  One of them lies on the lawn there, with a bullet through his brain.  We are still looking for the other.”

“Do you imagine that I can be of any assistance to you?” Granet asked.

“That is our impression,” Major Thomson admitted.  “Perhaps you will be so good as to tell us what you were doing here last night?”

“Certainly,” Granet replied.  “About half-past ten last night I thought I heard the engine of an airship.  We all went out on the lawn but could see nothing.  However, I took that opportunity to get my car ready in case there was any excitement going.  Later on, as I was on my way upstairs, I distinctly heard the sound once more.  I went out, started my car, and drove down the lane.  It seemed to be coming in this direction so I followed along, pulled up short of the house, climbed on the top of the bank and saw that extraordinary illumination from the marshland on the other side.  I saw a man in a small boat fall back as though he were shot.  A moment or two later I returned to my car and was accosted by two soldiers, to whom I gave my name and address.  That is really all I know about the matter.”

Major Thomson nodded.

“You had only just arrived, then, when the bombs were dropped?”

“I pulled up just before the illumination,” Granet asserted.

Thomson looked at him thoughtfully.

“I am going to make a remark, Captain Granet,” he said, “upon which you can comment or not, as you choose.  Was not your costume last night rather a singular one for the evening?  You say that you were on your way upstairs to undress when you heard the Zeppelin.  Do you wear rubber shoes and a Norfolk jacket for dinner?”

Granet for a moment bit his lip.

“I laid out those things in case there was anything doing,” he said.  “As I told you, I felt sure that I had heard an airship earlier in the evening, and I meant to try and follow it if I heard it again.”

There was a brief silence.  Granet lounged a little back in his chair, but though his air of indifference was perfect, a sickening foreboding was creeping in upon him.  He was conscious of failure, of blind, idiotic folly.  Never before had he been guilty of such miserable short-sightedness.  He fought desperately against the toils which he felt were gradually closing in upon him.  There must be some way out!

“Captain Granet,” he questioner continued, in his calm, emotionless tone, “according to your story you changed your clothes and reached here at the same time as the Zeppelin, after having heard its approach.  It is four miles and a half to the Dormy House Club, and that Zeppelin must have been travelling at the rate of at least sixty miles an hour.  Is your car capable of miracles?”