In a few minutes the destroyer was broadside on to the strange vessel and Lawless shouted a demand to know what ship she was. A pause ensued, and then, by way of an answer, a tongue of flame leapt from the stranger's port side and a shell crashed into the _Knat's_ funnel, just abaft the bridge. In a second the destroyer had swung round so as to present only her bows to the enemy and her machine-guns were hammering away as fast as they could be loaded. The duel lasted nearly ten minutes, the _Knat_ trying to manoeuvre into such a position that she could torpedo her adversary, the latter doing her utmost to frustrate this design. And all this time the two vessels were pounding away at each other with their machine-guns, circling around like two wrestlers before they come to grips. The enemy had the advantage in guns, which were far heavier than those carried by the destroyer, but the latter made up for this in speed and, being so small, proved an extraordinarily difficult target to hit. At last Lawless saw his chance to launch a torpedo and gave the word. The glistening, fish-like weapon leapt from its tube and, at the same moment, the enemy vessel started to swing round in order to avoid the fast approaching engine of death. But the manoeuvre had been carried out too late; the torpedo struck her just underneath the stern and there was a terrific explosion. The steamer heeled over on her starboard side, her bows lifted above the water, and then, with a roar of escaping steam, she dived stern foremost beneath the surface, and so to the bottom, fifty fathoms deep or more. The _Knat's_ boats had been launched immediately after the mine-sower was struck, and they at once proceeded to the spot where she had disappeared. But so swift had been the steamer's fate that not more than half a dozen survivors were picked up and, after pulling around for a while, the boats returned to the _Knat_. Early in the afternoon of the following day the _Knat_ put into Hull, and Lawless, having handed over his prisoners and written an official report of the engagement, went ashore with Trent. "By the way," said the latter, as they made their way towards a certain hostelry much favoured by naval and merchant service officers, "did you notice the _Cotswold_ moored just off the landing stage?" "No, I was below making out my report." His face expanded into a broad grin. "Then the chances are ten to one that we meet her skipper before the day's out. And if I don't pull his blessed leg you can strafe me for a Hun." As it happened they did meet this particular skipper, and in the very hostelry to which they were bound. He was in the smoking-room and, of course, did not recognise Lawless when he and Trent entered because, on the occasion of their exchanging courtesies, it had been too dark and foggy for either of them to identify the other. The Lieutenant, however, knew him at once by his voice, which was of a peculiarly hoarse quality.