RESIDENT ALIEN is based on the successful comics from Splitter Verlag and follows a crashed alien named Harry and his adventures on Earth. In the fourth season, Harry and his baby Bridget are stuck in captivity at Grey Moonbase, while on Earth, a shapeshifter named Manti has taken over Harry's body and pretends to be the real Harry Vanderspeigle. Harry eventually manages to escape the Greys and returns to Earth to confront Manti. In doing so, however, he must recognize that he may lack the necessary means to complete this task. Meanwhile, Asta and D'arcy desperately try to hide a secret from Ben and Kate, who are desperately looking for answers to the mysterious events they have experienced. At the same time, Sheriff Mike and Deputy Liv investigate a series of mysterious deaths in Patience - and Sheriff Mike increasingly begins to believe that there is no human hand behind them.