Douglas Quaid is haunted by a recurring dream about a journey to Mars. He hopes to find out more about this dream and buys a holiday at Rekall Inc. where they sell implanted memories. But something goes wrong with the memory implantation and he remembers being a secret agent fighting against the evil Mars administrator Cohaagen. Now the story really begins and it's a rollercoaster ride until the massive end of the movie.
 
http://www.imdb.com/title/tt0100802/