Daniel Jackson descubre que el Stargate fue activado en 1945 y un joven profesor pasó a través de él, sin volver nunca más. Junto con su prometida aún viva, el equipo SG1 descubre al profesor, ahora anciano, desnudo y atrapado en una fortaleza en decadencia, que contiene los secretos de una alianza antigua. ¿Podrán rescatarlo y escapar a la Tierra a tiempo?

Colonel O'Neill awakens and is told by new staff everything in the SGC is different because he was just revived after 79 years of cryogenic hibernation, as sole survivor of a disastrous SG-1 mission on a Goa'uld-ruled planet. He accepts to undergo a 'high tech hypnosis' to retrieve information of use in the present war against them, which is going badly, involving earth's ten endangered colonies on other planets. However Major General Trofsky, the new base commander, and his female assistant tell Daniel and Sam, in different sections, that each of them is the sole survivor: it's all make-believe to probe their brains about the weaknesses of earth and the Alliance of the four races. Meanwhile, Teal'c awakes on earth, where it took Dr. Frasier months to save him from death; there was no trace of his teammates, and he resigns when General Hammond refuses permission to keep searching. O'Neill hears Goa'uld language, gets himself free and discovers he's on a fake SGC, frees Sam and Daniel, only to be stopped by the female Goa'uld system-lord Hathor, who employs both Horus and Serpent Jaffa and demands the humans' help against her rival system-lords.