Jacub's father left for business, so there is currently no "man in the house". No wonder Jacub becomes responsible for everything happening in the building.
Sixteen years after the events of Mysteriet på Greveholm, a new family moves into the long-neglected castle. Left behind after the Olssons’ departure, the ghosts Jean and Staffan have spent years alone in the dilapidated halls and are delighted to finally have company, eagerly trying to make the newcomers feel at home. But as they settle in, they begin to discover that Greveholm is hiding far greater secrets than anyone ever imagined.
Carmen and Elena Iturrioz are sisters and partners in a laboratory inherited from their parents. Both carry out the cases that reach the laboratory, together with a team of collaborators. Each episode will stage a new story that arrives at the laboratory at the hands of characters seeking to find out their identity, recognize a son or a brother, gain access to an inheritance or identify a genetic disease, among others. they will reveal who they are; they will get closer to their own personal and family identity.