Old ships never die-not if Lieutenant St. Vincent Halfhyde and the irascible Captain Watkiss are in command. The old iron-clad Meridian steams south on her last journey under the British flag, on route to her new home in the Chilean Navy. Using the transfer of the ship as cover, Halfhyde and Watkiss are on a covert operation to protect British interests in South America from the encroachment of Germany.
Soon Halfhyde has an added mission: he must help Detective Inspector Todhunter from the Metropolitan Police track down the traitorous civil servant, Russell Savory, who has escaped from prison and is assumed on the run for South America. It's a race against the Germans as Halfhyde uses intrigue and double-cross-and a few clandestine meetings in dark South American alleys-to turn events in Britain's favor and save the Empire once again.