Synopsis by Hal Erickson
On the planet P3X562, Jack O'Neill (Richard Dean Anderson) comes in contact with some luminescent blue crystals--and is promptly infected by an alien species who generate an O'Neill replicant. The fake O'Neill takes place of the real one, assuming command of the SG-1 and setting out to locate Jack's estranged wife Sara (Harley Jane Kozak). When the authentic O'Neill revives, he joins Carter (Amanda Tapping) and Jackson (Michael Shanks) in a frantic search for his double, who will become dangerously unstable upon entering the earth's atmosphere. In the process, both O'Neills must come to grips with the death of Jack's son Charlie (Kyle Graham).
alien [not human], lookalike