Book 12 in the Gaunt's Ghosts series

An enemy prisoner demands to speak to Gaunt, throwing the Tanith First into a murderous web of secrets and lies that could decide the fate of the Sabbat Worlds Crusade.

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Even on leave, Gaunt's Ghosts find themselves in trouble... A dangerous enemy prisoner will only speak to Gaunt (who's apparently dead, if Imperial records are to be believed), and the Ghosts find themselves mixed up with criminal gangs.