London, 1894.

Inspector Henry Cutter is in an unconvivial temper. Then the murders begin. The first to die is Sir Aneurin Considine, a decorated but long retired civil servant, is found dead amongst his beloved orchid collection, killed by a wound inflicted with surgical precision.

Soon, other victims suffer similar fates. More men in powerful positions; more murders that are gruesome but immaculately orchestrated. The perpetrator comes and goes like a ghost, leaving only carefully considered traces.

Hot on the tails of this invisible adversary are Inspector Cutter, along with his hapless but endlessly enthusiastic sidekick, Sergeant Gideon Bliss. But as the pressure mounts, victims will start to look like perpetrators, murderers like truth-tellers, long-hidden failings will come resurface, and not even their very selves are safe from suspicion.