The bloated remains of a man are discovered bound to a derelict pier in Orkney and newly promoted DCI Lukas Mahler dispatches a team to investigate. But when the body is identified as Alex Fleming - Mahler's former colleague from his time in the Met - the case becomes personal.

Mahler's investigation takes him from his old stamping ground of London to the world of organised crime, and from sixteenth-century witch executions to Fleming's most notorious unsolved case: the 'Witchfinder' murders. Are the runic symbols found with Fleming's body proof the killer's struck again - or is there an even darker story to be uncovered?

With pressure mounting from all sides and demons from his own past surfacing, Mahler is faced with the most complex moral decision of his career.

The Queen of Highland Noir gets spookier and darker with every book! A compelling read! * Lilja Sigurdardottir *
In the Blood is a potent mix of true-to-life characters, gritty, authentic writing and a plot that kept me guessing until the very end - Margaret Kirk is one of the strongest voices in the current crop of excellent Scottish crime writers * Alison Belsham *
Top notch detective fiction with a little twist of something spooky. Five stars! * James Oswald *
Deliciously dark and pulse-pounding * Helen S Fields *
Lukas Mahler's third outing is an intriguing tale set on Orkney where the past and present collide, testing acting DCI Mahler to his limits both professionally and personally. Orkney is as much a star as Mahler, who becomes more compelling with every outing. Highly recommended. * Lin Anderson *

Margaret Kirk is a Highland Scot and a graduate of Glasgow University. She is the winner of the Good Housekeeping Novel Competition 2016 which she won with Shadow Man, her debut novel featuring the brilliant Detective Lukas Mahler. Find her on Twitter @HighlandWriter.