Release Message:  A relief crew en route to Titan in 5000 AD unwarily pick up hitchhikers that change them. Shortly thereafter the Doctor (Tom Baker), passing through the same point in space, is hitchhiked as well, but not Leela - a reject who must die.

Description:  "Contact has been made!" A relief crew en route to Titan in 5000 AD unwarily pick up hitchhikers that change them. Shortly thereafter the Doctor, passing through the same point in space, is hitchhiked as well, but not Leela - a reject who must die.