V'Ger: From the 1979 movie Star Trek: The Motion Picture. It is also referred to as "Where Nomad Has Gone Before". A giant and deadly alien cloud called V'Ger is approaching Earth destroying everything in its way. Poor V'Ger was actually an Earth probe called Voyager 6 created in the 20th century that happened to vanish in a black hole and was repaired by a race of living machines (maybe it was the Transformers) and then sent home to seek "the creator". Fortunately, Kirk's rival Captain Decker (who blames Kirk for the death of his father Commodore Matt Decker who took on the Doomsday device) sacrifices himself to merge with V'Ger and his bald girlfriend who is now a robot to become a new being. They/it zoom off to another dimension and do only God knows what.
(Image courtesy of Memory Alpha)