British blimps vs. German U-boats off the British coast circa 1916--as an English Intelligence officer leads a semi-private vendetta against a ruthless U-boat commander. Richard Shepherd, a Whitehall codebreaker, is wracked by grief and guilt when his fiancÃ‰e dies in the sinking of a France-bound nursing ship. What to do? What else but to kill the commander of UC62, the U-boat that did the dirty work: Otto Schiller, a.k.a. ""the Poet,"" an ambitious, amoral young captain. So, with the help of some sympathetic colleagues in Intelligence, Shepherd deserts his post and enlists in the Royal Naval Air Service, the branch involving the flying of those newfangled blimps. His initial plan? To make sure that a blimp bomb is dropped directly on Schiller's U-boat--with the assistance of data from those friends in Whitehall. After a few disastrous attempts, however, all defeated by the U-boat's minelaying expertise, Shepherd comes up with a more wily scheme: tricking Schiller into blowing himself up with his own mines! True, this elaborate plot requires major aid from an admiral (who just happens to be the father of Shepherd's new girlfriend). Also, Shepherd's bosses have dispatched an official to bring him back and charge him with desertion. Nonetheless, the plan succeeds--and two U-boats are sunk before Shepherd goes back to Whitehall a semi-hero. Awfully foolish and slow-moving, with vignettes from aboard the U-boat slogged in at regular intervals; but anyone with a passion for period-aviation will probably relish the airship-maneuvers along the coast--full of discomfort, chance, and Shepherd's fledgling fumbles.