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.