Ingvar suggests he and Inger team up to track down the mole in the Swedish police force, but Warren Schifford does his best to frustrate their efforts. As evidence begins to mount, possible leads emerge in relation to President Helen Tyler's disappearance, but Schifford insists everything points to the work of a single individual.

Swedish police search for a mole within their own ranks, while Inger Johanne leaves Ingvar behind and goes looking for the US president on her own. Meanwhile, Ingvar pays Warren a visit and some theories start to emerge about who might be behind the president's disappearance.

Inger Johanne wants to get help to the captive president but is surprised to discover the president doesn't trust anyone in her own ranks. Meanwhile, there are rifts within the FBI as conflicting stories emerge about who might be behind the kidnapping. Ingvar pays a visit to someone who will turn out to be a key figure in the investigation and to have links to Helen Tyler's past.