[1] During a bank robbery in Oslo, a lone robber holds a teller hostage and threatens to kill her unless the ATM is emptied within twenty-five seconds before the police can arrive.

The case goes unsolved until a police video evidence expert, Beate Lønn, surmises from the footage that the robber and the hostage knew each other.

Hole conceals evidence of his presence in Anna's flat, unable to prove that he himself is not the killer and believing that he is being set up for the crime.

After Hole uncovers another of Anna's former lovers who could be responsible for both her death and the robberies, Waaler goes after the new suspect to arrest him.

Hole deciphers the e-mail signature and finds that it stands for "Nemesis", the name of Anna's planned art show and the ancient Greek goddess of retribution.

Following Hole's exoneration for Anna's death, he and Lønn deduce that the robber is the widowed husband of the first robbery's murder victim, and that he killed his wife following her decision to leave him and elope with his older brother, who was the first suspect that had been found dead in Brazil.