A new anonymous letter leads to fresh evidence, but not everyone is happy to see the old murder case back in the spotlight. Wisting realizes he is being opposed by powerful forces within the police, as he keeps searching for the secret messenger.

A breakthrough in the case takes Wisting to Vilnius for a meeting with Interpol investigator Harriet Dunn. What is meant to be a simple questioning of a suspect becomes far more complex for both of them - both professionally and personally.