Galaxy Quest

The cast of an old 1980s space-adventure television series, Galaxy Quest, spend most of their days attending fan conventions and making promotional appearances. Though the series' conceited former star, Jason Nesmith, thrives on the attention, the other cast members—Gwen, Alexander, Fred, and Tommy—resent him and, to varying degrees, the states of their careers.

At a convention, Jason is approached by a group calling themselves Thermians, led by Mathesar, who request his help. Jason thinks they want him for a promotional appearance and agrees. The next morning, when the Thermians pick him up, Jason is hung over and does not grasp that the Thermians are aliens and that he has been transported to a working re-creation of the bridge of the NSEA Protector, the starship from Galaxy Quest. Believing he is on a set and must perform in character, he confronts the Thermians’ enemy, the evil warlord Sarris, who demands the "Omega 13", a secret superweapon mentioned in the final scene of the series, which has never been used and whose capabilities are unknown. Giving perfunctory orders, Jason manages to temporarily defeat Sarris.