Summer, 1940: Andy Holt has signed on as Second Mate in the SS Barranquilla, sailing in ballast from the Clyde for Nuevitas in Cuba. From there she'll be routed up the US seaboard to Halifax, Nova Scotia, assembly-point for homebound convoys. The homebound ones are the worst - U-boats prefer their victims to be fully laden. Andy has joined Quilla at the last minute and not with an easy mind, having just heard that his girlfriend Julia is pregnant. He loves her and is ready to do the honourable thing, but he could be away for another ten weeks or more. That's if he makes it. At the moment the odds are against any individual ship getting over “the pond” and back . . .