"I say, pater!" exclaimed Billy, suddenly remembering something in his pocket. "Here, take this. It will interest you. Forgot all about it before this." Peter took the proffered paper--a copy of the document found on the body of the dead German airman, setting a price upon Barcroft Senior's head. The train was on the move. Billy, with his head and shoulders still protruding through the window, waved farewells to his parents, then---- "Dash it all!" he shouted. "Butterfly--the donkey--ran away. Clean forgot to mention it." But Peter merely shook his head. The rumble of the train made the words quite inaudible. It was nearly seven in the morning when Flight-sub-lieutenant Barcroft arrived at Rosyth, after a long and tedious journey. Mists were hanging over the waters of the Firth of Forth. Even the lofty structure of the Forth Bridge was hidden by the grey bank of vapour. Service craft of all sizes and descriptions were feeling their way up and down the broad estuary, making the welkin ring with the discordant braying on their syrens and foghorns. "Have you seen anything of the 'Hippodrome's' boat?" inquired Billy of a petty officer on duty on the jetty." "'Hippodrome's' boat, sir?" repeated the man. "Why, the 'Hippodrome' got under way a couple of hours ago, along with the Seventh Destroyer Division, The Ninth's just off, sir." Barcroft rapidly reviewed the situation. Experience had taught him that there are often two ways of doing things in the Service--the official and the non-official. To be strictly in accord with the precedent he should have reported himself to the Admiral, giving his reasons why he missed his ship and getting a smart "rap over the knuckles." On the other hand he might be able to enlist the sympathies of one of the officers of the Ninth Destroyer Division and get a passage--provided the boats were proceeding to the same rendezvous. He resolved to put the latter proposition into effect; failing that, he would have to fall back upon the official routine. His luck was in. As he hurried across the caisson on his way to the jetty where the destroyers were berthed he overtook a lieutenant commander, whom he recognised as Terence Aubyn, a particular friend of Flight-lieutenant Fuller. "By all means," replied Aubyn when Barcroft had explained the circumstances and requested a passage. "We're pretty certain to fall in with the 'Hippodrome,' although I have as yet no idea of the position of the rendezvous. In fact, I have a couple of her men on board now. They got adrift in a copper punt last night, and were only picked up after the ship had left." "No further news of Fuller, I'm afraid?" remarked Barcroft. "Not a whisper," replied the lieutenant-commander as he ran briskly up the steeply sloping "brow" to the quarter-deck of the destroyer "Audax." And thus Flight-sub-lieutenant Barcroft found himself on board one of the newest type of destroyers bound for an unknown rendezvous somewhere in the North Sea.