The odd couple from Department Q, who made their debut in last year's novel Mercy, are back in another complex, original and gripping thriller.

Detective Carl Mørck and Syrian assistant Assad have a feisty new recruit, Rose, to help them investigate the 20-year-old murder of a young brother and sister.

They soon realise a group of feral boarding school students were responsible, but those youths and the some of the richest and most powerful men in Copenhagen.

A woman from the group, Kimmie, is scratching a living on the city streets and her former friends will stop at nothing to find her before she can reveal her secrets.

Past crimes lead to present murder in a book that, like Mercy, will delight fans of Nordic crime such as TV's The Killing and the books of Jo Nesbo and Lisa Marklund.

David Knights