torpedoes, but also to torpedo without warning. This was the only alternative except to abandon the submarine campaign altogether. Berlin accordingly instructed the submarine commanders not to approach on the surface any merchant or passenger vessel closely enough to get within range of its guns, but to keep at a distance and shell it. Had the commanders always observed these instructions the success of the mystery ship in sinking submarines would have ended then and there, though the influence of their presence upon tactics would have remained in force. The Allied navies now made elaborate preparations, all for the purpose of persuading Fritz to approach in the face of a tremendous risk concerning which he had been accurately informed. Every submarine commander, after torpedoing his victim, now clearly understood that it might be a decoy despatched for the particular purpose of entrapping him; and he knew that an attempt to approach within a short distance of the foundering vessel might spell his own immediate destruction. The expert in German mentality must explain why, under these circumstances, he should have persisted in walking into the jaws of death. The skill with which the mystery ships and their crews were disguised perhaps explains this in part. Anyone who might have happened in the open sea upon Captain Campbell and his slow-moving freighter could not have believed that they were part and parcel of the Royal Navy. Our own destroyers were sometimes deceived by them. The _Cushing_ one day hailed Captain Campbell in the _Pargust_, having mistaken him for a defenceless tramp. The conversation between the two ships was brief but to the point: _Cushing_: What ship? _Pargust_: Gordon Campbell! Please keep out of sight.