"The whole business seems a general muck-up, Greyhouse," observed the Commander-in-Chief, addressing the lieutenant-colonel. "There's something wrong somewhere. How can this confounded lighter be sunk in collision and shortly afterwards be blown up?" "There were two lighters, sir," replied Colonel Greyhouse. "It is quite possible that one was mistaken for the other." "As a matter of fact there were half a dozen," explained the Commander-in-Chief. "And all, except No. 5, are accounted for. That is so, Elphinhaye?" "Yes, sir," corroborated the secretary. "But the main reason why I came to see you, sir," said Lieutenant-Colonel Greyhouse, "was the affair of my missing officers. In the first instance they went off in a boat belonging to one of my lieutenants. I cannot conceive how they came to be on board the lighter. True, she was to be transferred to the R.A.F., but she left here under an R.N.V.R officer and crew." "Sub-lieutenant John McIntosh, sir, who reported from Donnikirk," announced the secretary, in response to his superior's inquiry --mutely expressed by the raising of his bushy eyebrows. "Exactly," agreed the Commander-in-Chief. "The situation required further information, and I have wired instructions to Mr. McIntosh to report immediately upon his return to-day." "Then there is the question raised by the presence of Captain Fennelburt----" "That," interrupted the naval officer, "is a matter that concerns the Air Force. I have no jurisdiction in the case." "But," persisted Colonel Greyhouse, "that officer visited Auldhaig Dockyard." "He called upon the Staff Captain, sir," reported the secretary, who appeared to have a knowledge of the movements of every stranger within the gates of Auldhaig Dockyard at his fingers' ends. "And yet the Air Ministry and Sheerness Air Station deny all knowledge of him," continued Colonel Greyhouse. "I was away on duty at the time he reported at my station, but curiously enough Captain Cumberleigh, one of the missing officers, entertained a suspicion of him. He communicated his doubts to my second-in-command, Major Sparrowhawk, who this morning reported to me on the matter. It is now his belief, although he scouted the idea at the time, that this Captain Fennelburt is a spy, or at least an impostor, masquerading as an R.A.F. officer, with certain shady motives behind him. That is why I came, in order to find out his alleged motives for visiting Auldhaig Dockyard."