French enjoyed that unconventional trip down the Inlet. Apart from the interest of the quest, the glorious weather and the charming scenery made it a delightful excursion. Borne on by the current, they first hugged the salt marshes of the northern shore, then heading out towards midchannel, they passed the post on Careg-ddu and rounded the point at the Llanelly rifle range. They kept inside the long training-bank or breakwater and, passing the entrance to Llanelly harbour, stood out towards the open sea. From the water the highlands north and south looked rugged and picturesque, and even the dingy buildings of the town became idealised and seemed to fit their setting. French took frequent bearings so as to be able to plot their course on the map. The crate had been settling down steadily, and now only about two inches of freeboard showed, every tiny wavelet washing over it. The rope had been carefully coiled so as to run out easily when the time came. Presently the crate was entirely awash and the air escaping through the upper holes bubbled as the little surges covered them. Then it was below the surface, showing like a phantom under the waves. At last, just one hour and seven minutes after they had left the bridge, it slowly vanished from sight and the rope began to run out. “That will do,” French said as soon as he had taken bearings. “That’s all I want. We may haul it up and get ashore.” They followed the example set by Mr. Morgan, and pulling up the crate until the top was showing beneath the surface, made the rope fast to the after-thwart and pulled for the Burry Port harbour. There they beached their burden, the sergeant undertaking to salve it when the tide fell. French, delighted with the result of his experiment, hurried to the hotel and plotted their course on his map. And then he was more delighted still. The crate had passed within fifty yards of its previous resting-place. It was true it had gone nearly half a mile further, but that was to be expected and was attributable to the greater fall of the tide. That the crate had been thrown from the Loughor bridge on the night of the 21st, 22nd, or 23rd of August French had now no doubt. The first problem of the investigation had therefore been solved and he congratulated himself on having made so brilliant a start in his new case. But as was usual in criminal investigations, the solution of one problem merely led to another: How had the crate been transported to the bridge? There were three possibilities: by means of a handcart, a horse cart or a motor lorry. All, however, had the serious objection that it would take at least three men to lift the crate over the parapet. Murders, of course, were sometimes the work of gangs, but much more frequently they were carried out by individuals, and French would have preferred a theory which involved only one man. However, there was nothing for it but to follow the theory which he had.