We all ran out, but no one was there, and Walters’ cabin door was fast.

I was quickest, and ran out of the saloon, but there was no one nearer than the forecastle-hatch in one direction, and on the other as I ran up the ladder there was the man at the wheel, one of the men we had secured, while the other was seated on the bulwark talking to him and smoking.

“What could it have been?” I thought, for a shiver of dread had run through me, a dread that some one had been listening, and overheard the doctor’s words.

But the next moment I laughed, and went back to those who were examining the various cabins.

“All right,” I said, pointing upwards, “that was it; I did not properly fasten up that sky-light, and it fell down.”

It was exactly as I said, for there was the window I had stuck open shut closely down.

“I was afraid that some one had been listening to what I had planned,” said Mr Frewen.

“So was I, sir,” I said, “but we’re all right. The men were both at the wheel.”

The next minute we were all in consultation again. I say we, for I was quite made one of them, young as I was. Then the matter was thoroughly discussed, for Mr Frewen’s plan proved to be not so easy on consideration as we had at first supposed.

“You see, gentlemen,” said Mr Brymer, “it’s one thing to set a trap, and another to get your rats to walk into it. How were you thinking of giving it to them?”