North London: the Belgian Detective and his loyal companion answer a desperate letter from a widow at 19 Marlowe Terrace, a drab narrow house where something has been knocking, scraping, and whispering for weeks — a table moves by itself in the parlour, a thirteen-year-old girl with eyes too old for her face laughs in the dark, and from somewhere inside the walls a dead husband's voice calls his wife by name; as the neighbours say trickery and the children say nothing, a sister who kept secrets she was never asked to explain, a neighbour whose kindness hid something patient and cruel, hidden passages between the houses that no one was meant to find, a severed hand discovered in a toy chest, and a child gone missing in the walls force the detective to separate the living from the dead and the guilty from the merely afraid; inspired by historical crime of its era while remaining entirely fictional, The Voice in the Wall is an original Golden Age–style mystery about haunted houses, hidden passages, and the discovery that the dead do not knock upon walls but the secrets they leave behind never stop speaking.