16 Urgo (HD)
22 Nemesis (1)
08 Demons (HD)
- Season: 3
- Episode: 21
- Prod. code:
- Network: Showtime
- Genre: Sci-Fi & Fantasy
- Rating: 12 (UK)
- Director: Peter DeLuise, Martin Wood, Andy Mikita, William Waring, William Gereghty, David Warry-Smith, Peter F. Woeste, Brad Turner, Mario Azzopardi, Ken Girotti, Charles Correll, Jonathan Glassner, Dennis Berry, Bill Corcoran, Robert C. Cooper
- Writers: Jonathan Glassner, Brad Wright, Robert C. Cooper, Joseph Mallozzi, Paul Mullie, Damian Kindler, Peter DeLuise, Katharyn Powers, Alan McCullough, Ronald Wilkerson, Tor Alexander Valenza, Michael Greenburg, Heather E. Ash, Jeff King
- Producer: Brad Wright, N. John Smith, Robert C. Cooper, Michael Greenburg, Richard Dean Anderson, Joseph Mallozzi, Paul Mullie, Andy Mikita, John G. Lenic, Ron French
- Cast: Amanda Tapping, Christopher Judge, Michael Shanks, Richard Dean Anderson, Don S. Davis, Gary Jones, Teryl Rothery, Dan Shea, Ben Browder, Beau Bridges, Claudia Black, Corin Nemec, Tony Amendola, Carmen Argenziano, Peter Williams, Bill Dow, Eric Breker, Cliff Simon, Colin Cunningham, Peter DeLuise, Laara Sadiq, Dan Payne, Martin Christopher, Tom McBeath, Ronny Cox, Lexa Doig, David Palffy, Gary Chalk
- Plot: SG-1 finds a Mayan ziggurat in a lepton-rich environment on planet P7X-377; inside is a crystal skull that makes Daniel a ghost. Daniel's grandfather Nicholas Ballard found a similar skull in Belize and helps out.
- Synopsis: SG-1 finds a Mayan ziggurat in a lepton-rich environment on planet P7X-377; inside is a crystal skull that makes Daniel a ghost. Daniel's grandfather Nicholas Ballard found a similar skull in Belize and helps out. When they return to the planet, giant aliens who have vaguely humanoid but insubstantial forms, appear and return Daniel to normality.