He shook his head. "I must look in for an hour. It doesn't matter what time though; there's always someone there till eight o'clock."
"I shall try and bring Campbell back with me by the mid-day train," I said. "Then we can have a hunt for the diamonds before you start."
"That's the idea," he replied approvingly. "With any luck it ought to be a very interesting and profitable afternoon."
He hoisted himself off the sill, and, coming up to where I was standing, helped me on with my coat.
"I'll row you ashore now," he added, "and if you'll let me know when to expect you I'll be waiting for you at Pen Mill."
"But how about the house?" I objected. "We oughtn't to leave it empty."
"I've only got to tip the word to my man Jenkins," he replied. "He'll take damned good care that nobody lands on the island."
We made our way downstairs, and, shutting the front door behind us, we set off at a brisk pace for the landing-stage.
The motor-boat, which had slewed round with the tide, was now lying with her nose towards the island, and Jenkins himself—a stalwart figure in white slops—was leaning pensively over the iron railing. As soon as he saw us he drew himself up and saluted.
We paddled alongside, where Bobby gave his instructions; and then, pulling straight across the estuary, ran in under the end of the jetty. Except for an aged fisherman mending his nets the place was entirely deserted.