When does Servant return?

Lauren Ambrose, Toby Kebbell, Nell Tiger Free and Rupert Grint star in all four seasons of the series. The series takes place in the household of Dorothy and Sean Turner, a couple in Philadelphia who hire a young nanny to be the live-in nanny of their infant son, Jericho. However, Jericho is dead and has been replaced by a reborn doll, which a traumatized Dorothy believes is the real, still-alive Jericho, leading her family to act accordingly. Leanne's arrival unearths dark secrets of both her and the family. The show received high praise from Guillermo del Toro and Stephen King.
Dorothy and Sean Turner experience a fracture in their marriage after the death of their 13-week-old son, Jericho. The couple undergo transitory object therapy using a lifelike reborn doll after Dorothy experiences a psychotic break. The doll was the only thing that brought her out of a catatonic state following Jericho's death.