Right from the start the whole exercise seemed doomed. When he heard he was to take part in one of Churchill's most audacious, some would say foolhardy, operations, Lieutenant-Commander Donald Cameron reckoned expendability was in the air. With a reduced complement, minimal supplies & armament, Cameron is given the command of a shaky old P-class destroyer joining two others in a similar state for the short crossing to the French port of Brest. There they are to penetrate the port & land a detachment of commandos to blow up the huge German U-boat pens.
When the Senior Officer's ship is blown up & the commandos fail to make the return rendezvous at the quayside, control of the operation falls to Cameron. Knowing that German warships are in the offing, he decides to creep inland, up the shallows of the Rade de Brest & make contact with the Resistance. It may seem hopeless but to attempt a dash to sea without support would be suicidal