Jussi Adler-Olson, Mercy, translated from the Danish by Lisa Hartford (London: Penguin, 2011 [2008]). A bravura start to the Department Q series: powerful, gripping and moving in equal measure  5 stars

Opening sentence: She scratched her fingertips on the smooth walls until they bled, and pounded her fists on the thick panes until she could no longer feel her hands.

On Friday 13th May, the author of Mercy joined John Lloyd, contributing editor on the Financial Times, to discuss his novel on BBC Radio 4. There was an entertaining clash of views: while Lloyd felt the book was ‘terribly, terribly, terribly dark’, Adler-Olsen thought Lloyd ‘completely wrong – it’s a very funny story in many aspects’. Having finished the novel today, I’ve come to the strange conclusion that they’re both right: Mercy will take you to the very darkest of places, while also somehow retaining the capacity to make you laugh out loud.

Mercy is the first in the ‘Department Q’ series, published in Denmark to great acclaim in 2008, and is the winner of a clutch of crime fiction prizes, including the Danish Reader’s Book Award. The novel introduces Copenhagen detective Carl Mørck, an outstanding investigator whose erratic behaviour following a traumatic shooting gets him kicked upstairs to lead the newly formed Department Q. Its remit: reopening and solving cold cases. Except being kicked upstairs actually means being kicked downstairs to a pokey office in the basement, without any investigative support other than chauffeur, cleaner and beverage-maker Assad.

The first case taken up by Mørck is that of rising Democrat politician Merete Lynggaard, whose sudden disappearance five years previously has never been satisfactorily explained. Everyone, including Mørck, assumes that she is dead. But is she?

Mercy is a beautifully constructed crime novel, weaving an account of Merete’s story since 2002 into Mørck’s investigations in present-day 2007. The movement between these strands creates a beguiling momentum that carries the reader forward in anticipation of the moment when – just maybe – the two narratives will intersect.

Merete’s tale is extremely dark and easily the most powerful part of the narrative: the crimes committed against her are horrifying, although the author manages to avoid the pitfall of crude misogynism through a compelling examination of how this young woman attempts to resist the powerful forces bent on her destruction.

The story of Mørck’s investigation into Merete’s case is lighter, in spite of his struggle with the trauma of a past shooting. Both his tussles with police colleagues and his developing relationship with Assad, an unlikely assistant sleuth with a few secrets of his own,  provide genuine moments of humour, although these are never allowed to interfere with the progression of a first-class police procedural.

Interestingly, I managed to work out the ‘solution’ to the mystery at the heart of Merete’s story quite early on. Even more interestingly, this didn’t matter to me in the slightest. Mercy was such a quality reading experience that my enjoyment of the text wasn’t remotely impeded. I’m already impatiently looking foward to the second novel in the series, Disgrace.

An extract from Mercy is available here. With thanks to Penguin for providing Mrs Peabody Investigates with a review copy.

Mrs. Peabody awards Mercy an outstanding 5 stars.