A cold-blooded killer strikes at the hottest moment: the new head of a sauna-stove company is murdered – in the sauna. Who has turned up the temperature and burned him to death? The evidence points in the direction of Anni Korpinen – top salesperson and the victim’s potential successor at Steam Devil. And as if hitting middle age, being in a marriage that has lost its purpose, and struggling with work weren’t enough, Anni realises that she must be quicker than both the police and the murderer to uncover who is behind it all – before it’s too late.