Alistair MacLean has called Brian Callison's first novel ""the best war story I have ever read."" Others may find it a somewhat contrived series of simple-minded mistakes and unexplained motives to rig a fantastic World War II drama. Unverified orders, treason, sabotage and disastrous ill-luck shepherd the British freighter Cyclops off its course into an annihilating U-boat ambush. The truth is submerged for 25 years until the discovery of the Cyclops and her wrecked convoy in the shallow, enclosed harbor off a deserted island. The journal of Cyclops' First Mate Kent conveniently surfaces to disclose the top-secret cargo of the ship--five million pounds sterling and the new communications codes from the Admiralty. Callison's characterizations are slight with the exception of the sinister radio operator Larabee (an unsurprising subversive) and the slightly ridiculous Captain Evans. But there is lots of homely detail (that everpresent pack of Players) and the plot is paced expertly.