In 1809, working undercover for the Admiralty's Secret Department, Captain Nathaniel Drinkwater goes ashore and mingles with the dregs of London's dockland. Disguised as a Merchant Marine shipmaster of low character, he encounters a known French agent in a brothel and advertises his plans to carry military cargo to Russia.
Intended to drive a wedge between Napoleon and his new ally, Czar Alexander, Drinkwater's mission is disrupted by tempestuous weather and a lost escort — a gun-brig commanded by his friend and protege. Reaching the British-occupied island of Helgoland, Drinkwater takes great personal risk by resolving on a bold course of action that is not endorsed by the Admiralty.
In the aftermath of a typhoon, Captain Nathaniel Drinkwater brings His Britannic Majesty's frigate into the shelter of the Pearl River on the China coast. Seeking the means to refit, he is unwittingly entangled in bizarre events following the British occupation of Macao and Admiral Drury's attack on Canton.
Initially relieved to be assigned the straightforward duty of a convoy escort to Penang, Captain Drinkwater quickly discovers that the convoy's cargo contains a mysterious quantity of silver and a single passenger. An apparently routine task is suddenly complicated by the resurrection of an old, embittered hatred, and Captain Drinkwater finds himself drawn inexorably by treachery, greed, perversity, and cruelty towards a climactic rendezvous in the remote tropical rain forest of Borneo.