minutes the sea, for a space many hundred yards in diameter, was covered with dead fish--about ten times as many, the officers reported, as could have been killed by the usual depth charge. The _Christabel_ and the ship she was guarding started to rejoin the main convoy, entirely satisfied with the afternoon's work. Indeed, they had good reason to be; a day or two afterward a battered submarine, the _U C-56_, crept painfully into the harbour of Santander, Spain; it was the boat which had had such an exciting contest with the _Christabel_. She was injured beyond the possibility of repair; besides, the Spanish Government interned her for "the duration of the war"; so that for all practical purposes the vessel was as good as sunk. V Discouraging as was this business of hunting an invisible foe, events occasionally happened with all the unexpectedness of real drama. For the greater part of the time the destroyers were engaged in battle with oil slicks, wakes, tide rips, streaks of suds, and suspicious disturbances on the water; yet now and then there were engagements with actual boats and flesh and blood human beings. To spend weeks at sea with no foe more substantial than an occasional foamy excrescence on the surface was the fate of most sailormen in this war; yet a few exciting moments, when they finally came, more than compensated for long periods of monotony. One afternoon in November, 1917, an American destroyer division, commanded by Commander Frank Berrien, with the _Nicholson_ as its flagship, put out of Queenstown on the usual mission of taking a westbound convoy to its rendezvous and bringing in one that was bound for British ports. This outward convoy was the "O Q 20" and consisted of eight fine ships. After the usual preliminary scoutings the vessels passed through the net in single file, sailed about ten miles to sea, and began to take up the stipulated formation, four columns of two ships each. The destroyers were moving around; they were even mingling in the convoy, carrying messages and giving instructions; by a quarter past four all the ships had attained their assigned positions, except one, the _René_, which was closing up to its place as the rear ship of the first column. Meanwhile, the destroyer _Fanning_ was steaming rapidly to its post on the rear flank. Suddenly there came a cry from the bridge of the _Fanning_, where Coxswain David D. Loomis was on lookout: "Periscope!"