Ari Jónsson, a successful lawyer, is appointed defence council in what looks like an open-and-shut criminal case. The victim is an elderly art collector who had been brutally assaulted in his home and left for dead - evidently in a robbery gone wrong. The suspect is a homeless man with a long trail of convictions.
Ari's client has a sister, Milla, who flies in from Copenhagen to rally to her brother's side. Milla is convinced he's innocent. She discovers that the victim's business partner had left the country just hours after the attack and, with Ari's help, sets about unravelling their shady past.
Ari's renewed interest in the case gives way to growing doubts about what's actually motivating her quest. He suspects that she knows more about what happened the night of the assault than she's letting on.