Cassie Maddox

Cassie Maddox is the Dublin Murder Squad detective and undercover specialist in Tana French's novel The Likeness — Rob Ryan's partner from In the Woods, now operating in a different case with a premise so improbable it strains even the characters' credulity: a murdered woman is found who is physically identical to Cassie and is living under an identity that Cassie used years ago during an undercover operation. Cassie goes back undercover — as the dead woman, in her house, among her friends — to find the killer.

French uses the doppelgänger premise to explore questions of identity, belonging, and the seductive power of alternative lives. Cassie's immersion in the dead woman's world — her house in Wicklow, her tight-knit group of graduate student housemates — reveals something Cassie herself has been missing, and the novel's tension comes as much from what she risks wanting as from the danger of the investigation itself.

French's Dublin Murder Squad novels are among the finest crime fiction being written — each book focuses on a different detective, building a world through accumulated perspectives rather than a single series protagonist. The Likeness is widely considered one of her best.

Read In the Woods first, then The Likeness.