Thomas F. Malone is an Irish-born New York police detective, "detailed to the Butler Street station in Brooklyn" before going on indefinite medical leave. A "Dublin University man born in a Georgian villa near Phoenix Park," he is said to have "the Celt's far vision of weird and hidden things, but the logician's quick eye for the outwardly unconvincing.... In youth he had felt the hidden beauty and ecstasy of things, and had been a poet; but poverty and sorrow and exile had turned his gaze in darker directions, and he had thrilled at the imputations of evil in the world around." This morbid streak is offset by a "keen logic and a deep sense of humour".
At the age of 42, he investigates mysterious disappearances in the Red Hook neighbourhood of Brooklyn. At one point he questions the elderly recluse Robert Suydam, whom he suspects of skullduggery. His exploration of the catacombs below Red Hook leave him psychologically devastated. ("The Horror at Red Hook")
Thomas Malone is one of the investigators sent by J. Edgar Hoover to investigate a series of bombing alongside Bureau of Investigation agent Miranda Keller (EXP:Miskatonic).