It is 1936. Pompey Casmilus (the heroine of Smith's debut, Novel on Yellow Paper) lives in London with her beloved Aunt, bothered by the menace of German militarism, bothered too by the humbug which confronts it, bothered most of all by her hopeless love affair with Freddy. Its ending plunges Pompey into melancholy; six months of rest and recuperation are prescribed and Pompey goes to Schloss Tilssen on the northern German border, only to fall in with a strange band of conspirators: the plum-coloured Mrs Pouncer, the absent-minded Colonel Peck and the dashing Major Tom Satterthwaite, whom Pompey comes to love. How Pompey gets into uniform and becomes a spy is only one of the astounding events in this extraordinary novel which, on a serious level, is also about a powerful investigation of power and cruelty in a world preparing for war.