Erica's sister Anna is visiting at the same time as the TV program "Antiques cubed" is in town to record at the castle in Fjällbacka. When Anna runs into the TV host for the show, Claes Wager, sparks quickly evolve into a flirt between the two of them. During preparation at the castle Anna is the one to find Linda Hamrin unconscious from an overdose of medicine. Both Erica and Patrik are dragged into the case when only a day later a man, Hasse Wennerman, is killed and the rumors of an affair that led to Linda's overdose spiral up into a big conflict. The old painting, Hasse Wennerman brought to the antique show, is also missing and when it is found among Annas belongings, Erica gets a hard time trying to prove her sisters innocence.
—Tre Vänner