“If those tracks on the sand happen to be his,” he said, “then we've got at least one bit of luck to start with.”

Wendover, coming to the chief constable's side, saw the footprints of two men stretching clean-cut along the beach until they grew small in the distance.

“We'll go down there and see what we can make of it,” Sir Clinton suggested. “I've telephoned to Armadale to come out from Lynden Sands and meet us. It's handy that these tracks stretch out in that direction and not into the other bay.”

They descended a steep flight of steps cut on the face of the cliff for the convenience of hotel visitors; and when they reached the sands below, they found the footprints starting out from the bottom of the stair. Sir Clinton opened his attaché-case and pulled out Paul Fordingbridge's shoes, which he had procured at the hotel.

“The boots told me that Fordingbridge had two pairs of shoes, both of the same pattern and both fairly new; so it should be easy enough to pick out his tracks, if they're here,” he said, taking one shoe and pressing it into the sand to make an impression of the sole. “That looks all right, squire. The nail pattern's the same in the shoe and the right-hand set of footmarks.”

“And the mark you've just made is a shade larger than the footprint,” Wendover commented, to show that he had profited by Sir Clinton's lesson of the previous day. “That fits all right. By the way, Clinton, it's clear enough that these two fellows met up at the top of the stairs and came down together. If they'd met here, there would have been a second set of tracks for Man No. 2, which he'd have made in coming towards the foot of the stairway.”

Sir Clinton nodded his agreement with this inference, put the shoes back in his attaché-case, and set out to follow the tracks across the sands. In a short time they passed Neptune's Seat, where Sir Clinton paused for a few moments to inspect the work of his diggers.

“That seems an interminable job you've set them,” Wendover commented as they walked on again.

“The tides interfere with the work. The men can only work between tides, and each incoming tide brings up a lot of sand and spreads it over the places they've dug out already.”

“What are you looking for, Clinton, damn it? It seems an awful waste of energy.”