Holiday (S02E17)

When the SG-1 team stumbles upon the chamber of former Goa'uld system lord Ma'chello, they fall victim to his powerful body-swapping invention. Ma'chello takes on Dr. Daniel Jackson's body, and the young archeologist finds himself trapped in the body of an old, dying man. In Daniel's body, Ma'chello flees Stargate Command and gets a taste of life on Earth for the first time, while Daniel lies on his deathbed in the hospital. In an attempt to help their friend, Col. Jack O'Neill and Teal'c bring the invention to Stargate Command, where they accidentally trigger it and find themselves trapped in each other's bodies. When Ma'chello is tracked down and returned to Stargate Command, he declares that the machine's process is irreversible. That, however, is not an answer that O'Neill or Capt. Samantha Carter is prepared to accept.... (Metro-Goldwyn-Mayer (MGM))