Nothing's ever simple for 17th-century spy Thomas Chaloner as he is thrust into several investigations within hours of returning from Tangier.
His main consignment seems petty: discovering who has been stealing bricks from the house being built for his master the Earl of Clarendon.
Then there's the assassination plot against the Earl's architect, detailed in letters apparently written by the unpopular Queen Katherine.
Also worrying is the rivalry between two groups of nobles, the Adventurers and Piccadilly Company, who both want control of empire building and slave trading in Africa.
Bodies mount up in all the cases, and an increasingly desperate Chaloner realises there are links with his recent undercover mission to Tangier.
Among the many suspects are Chaloner's friends and colleagues in a story that blends adventure and whodunnit in Gregory's usual satisfyingly convoluted fashion.