In London for a booksellers' conference, Lark shares a small flat with Ann Veryan, an English teacher from Georgia. While Lark pursues collectible books, Ann explores London for the first time. They've struck up a friendship with Milos Vlacek, a Czech refugee waiter from the conference hotel. On their way home from a matinee of Macbeth at the Barbicon, Milos is stabbed on the Underground. Minutes earlier he had given Ann a manuscript to carry for him in her huge needlepoint purse.

What do you do if you're a foreigner trapped in a British police investigation? Lark sends for husband Jay, who was coming over for a police conference. She also mails a copy of the Czech-language manuscript to her father, who has a colleague capable of translating it. Milos is not dead, but his injuries are grave. When Lark's landlady is murdered, police suspicion of Lark and Ann intensifies. Jay may arrive to find his wife in the Old Bailey. Clearly Lark has to Do Something.

Questions abound. Who is Milos? Why was he stabbed? What's in the manuscript? Who would kill an inoffensive elderly Englishwoman in her own hallway? When Milos, still very ill, goes missing, Lark and Ann venture out into the English countryside to find him—with explosive consequences.