“What information we have is not much,” said Wainwright, “but such as it is you shall have it before you go down to the sands. Dr Rixon is there but we may assume from the details that the body is Roland Chastelnau, the younger brother. They’re bringing him up on a hurdle. A further search has been made of the sands and the dunes, as high as the tide might reach. We have found a broken lantern and a damaged shotgun, empty and soaked by sea-water, not far from where a body would be swept away. Whatever may have passed between the brothers, it looks very much as if both of them died at flood tide last Sunday night. A great tragedy.”

The inspector frowned. Then he added, “You notice, gentlemen, I say ‘died’ and not ‘drowned.’ If Abraham Chastelnau went down in the quicksands we shall never have a certain verdict.”

“And in that case,” I said, “you will never know if he died-or how.”

“We are not likely to see him again, doctor. If we do happen to find him alive, of course, I shall have some strong questions to put to him. He may be the murderer of his brother Roland. That would be something, as they say, in a place like this.”

By this time I could not help feeling grateful that we enjoyed the protection of Lestrade. In consequence, the Lincolnshire officer acted as if the case had been taken out of his hands and put into ours. Had Abraham Chastelnau survived, I believe Albert Wainwright would have been well-pleased to bring a charge of murder against him. As that seemed unlikely, he lost interest.

The inspector opened the barrack-room door and stepped out on to the small iron platform with its ladder to the sands. He paused, framed by the lintel of the door.

“As to the lantern-room, gentlemen, the mechanism is clockwork, as it is in all these beacons. Similar to an old-fashioned grandfather clock but on a larger scale. A stout iron chain bearing a weight is cranked up to the top. Its gradual descent for eight hours is controlled by a governor, as is the case with a pendulum in a clock. And just as the weight in a clock turns the minute and the hour hands, so the descent of the weight here turns the banks of reflectors which direct the light of the lantern as a single beam across the sea. Until we have new keepers, a deputy keeper will come over from Freiston Shore to crank it up, to wind the clock and governor. He will also ensure that the reservoir tanks are full of paraffin oil to keep the lantern burning. They will send new keepers from Lynn in a day or two. Until full tide, my constable will be at hand to answer your questions and help you as you may require.”

“One moment if you please, Mr Wainwright,” said Holmes courteously, “What were the duties of the keepers while they were here?”

“One man is on watch at a time. He notes the speed of the wind, the pressure of the barometer and so forth. One of them must polish the lenses of the reflectors every morning. He also cleans the panes of the lantern windows when necessary. Of course, ours is nothing but a local beacon. Not much shipping comes near us.”

“As Mr Gilmore says,” remarked Holmes, “It is like the church tower, a beacon for those on the shore and the mudflats after dark.”

The inspector left us the run of the Old Light, with a uniformed constable at the foot of the iron ladder. Presently we climbed down and trudged over the marsh to a broad ribbon of sand where the discovery of Roland Chastelnau’s body had been made. Dr Rixon had finished his examination and four men were bringing the corpse up the beach on a white sheep-hurdle.

Of the two men following the hurdle, one was Mr Gilmore and the other was recognisable as Dr Rixon himself, if only because he wore a tweed suit and cap, and carried a black medical bag. I introduced myself. On such a coast, this could not have been the first time he had been called to the scene of a drowning. He appeared to regard the duty as an entirely impersonal matter and had no objection whatever to discussing it.

“It would seem that the poor fellow was drowned,” I ventured.

“The inquest will find it so,” he said readily, “Of course, we must see what an autopsy reveals.”

“He was not marked about the face or head?”

“No. There was post-mortem staining, as one might expect, but he would scarcely be dashed against rocks on such a shore as this. Not with the flood tide as quiet as it usually is in these parts.”

Sherlock Holmes joined us.

“Permit me to ask, Dr Rixon, does there exist a photograph of either of the two brothers?”

Rixon put on a scowl of perplexity.

“I do not think so-Mr Holmes, I presume? I should be most surprised if there were. They were alike in many features as most brothers are but this is Roland and not Abraham. We have known them all their lives.”

“And his pockets? Is there nothing there to prove his identity.”

My friend tapped the pockets of the faded and bedraggled jacket on the corpse. It seemed evident from his face that his fingers felt nothing.

“No,” said Dr Rixon, disinclined even to issue a reprimand as Holmes slid a hand into each of the side-pockets, “No, Mr Holmes. I think under the circumstances, whatever Scotland Yard may consider…”

“Only relics of the beach such as this?” Holmes asked innocently. He was holding between his finger and thumb a dun-coated pebble that might have been the twin of the one presented to us by Miss Chastelnau. “Or this?”

There were three or four of these objects altogether. Yet even before Dr Rixon could reply, Holmes dismissed the matter for him.

“It is common enough,” my friend added with a shrug, “the detritus of the beach and its shallows will easily find its way into the folds and wrinkles of clothing, after several days of washing to and fro by the tides.”

I was sure he had thrown the pebbles away. They were no longer in his hand. On reflection, I had no doubt that they had been transferred subtly from the pocket of Roland Chastelnau to that of Sherlock Holmes.

5

In the absence of Albert Wainwright I assumed that we might spend much of the coming night searching the drawers and cupboards of the Old Light before the inspector’s return. I did not anticipate that in the meantime we should come close to sharing the fate of the unfortunate Roland Chastelnau.

On our return to the foreshore lighthouse, with only a uniformed constable standing temporary guard on the wet sand below, we climbed the iron ladder again. The constable called up and informed us that he would be leaving shortly. In another hour or so the sand on which he stood would be covered by the tide. Holmes thanked him and then moved across the room to the wooden ladder under the trapdoor of the lantern. His feet disappeared and I heard him moving about above me. Then his face reappeared in the opening of the trap.

“Come up, Watson! The pebbles can wait until later. See what a wonderland is here!”

I followed him up to the tall lantern-room. It was, in effect, two rooms in one, the upper level occupied by the machinery of the powerful reflectors. Within its glass dome, formed by the large window-panes, the air was still warm from the autumn sun, the heat reflected by silvered metal. The space was also filled with a strong mineral tang of paraffin oil from the iron reservoir tanks below the apparatus.

To do justice to the intricate design would test the reader’s patience. At the lower level of the lantern room, where we stood, there was a table with the keepers’ log-book. On a central shaft a heavy iron weight on its chain descended slowly through the eight hours of its cycle, turning the banks of reflectors overhead steadily. When cranked up, the chain was wound on a large drum above us. A tall case in plain wood with a white enamelled dial and two keyholes, like a long-case “grandfather” clock, controlled the mechanism. The hole on the left appeared to be for winding up a weight whose descent turned the clock hands of a dial, while on the right, the same key wound a governor of some kind, which kept the mechanism of the reflectors at an even pace.