Department Q solves the unsolvable.

So when a file on the brutal murder of a brother and sister 20 years ago lands on the desk of Detective Carl Mørck he doesn't understand why.

Because the killer has already been found, and the case is closed.

Why has it turned up on Carl's desk? And who put it there?

'The new 'it' boy of Nordic Noir' The Times

'Gripping story-telling' Guardian

'Mesmerising... As impressive as it is unnerving' Independent

'Engrossing' Sunday Express