When a secret base abandoned by the ancients is found buried in the ice of Antarctica, the Atlantis team is recruited for the most daring Stargate mission yet: a one-way expedition to the distant Pegasus galaxy. There they discover an advanced but deserted city on the ocean floor and encounter the Wraith, a sinister new enemy that threatens human life everywhere. Stargate Atlantis stars Joe Flanigan in the leading role of John Sheppard, Torri Higginson as Dr. Elizabeth Weir and Rachel Luttrell as Teyla Emmagan. In season 2, Jason Momoa joined the cast in the role of Ronon Dex, while David Hewlett played Rodney McKay.