Valentin Rochefort, professional duellist and down-at-heels aristocrat, arranges the assassination of Henri IV, King of France. Fleeing from the consequences, he makes for England, on the way picking up two companions - a young boy, Dariole, and a ship-wrecked 'demon'. Dariole is discovered first to be a girl, and then to be Rochefort's sister; the 'demon' is Tanaka Saburo, a Japanese samurai on ambassadorial mission to England from the Shogun; and Rochefort is found by a pack of Hermetic mages and conspirators, who want him to arrange the same thing for King James I/VI of England as he did for Henri of France. Rochefort is blackmailed into arranging the death of King James at the performance of a Hermetic magic play. Meanwhile, Dariole is busy making forays into Shakespeare's theatre as England's first (and worst) female actor . . . 1610 really isn't Rochefort's year - And as the play's performance and the assassination approach, Rochefort's dreams of the future that may spring from this crucial year grow increasingly stranger and more contradictory. He realises he must act - but, how? What is the right choice? And how much of the future will depend on what he does?