SG-1, when they find yet another timetravel device, Jack decides to change the timeline so his son Charlie is not killed. Jack is the only one to travel back in time, and somehow he retains the knowledge of both timelines. Story from his pov, reflecting over the changes. Requirements of new timeline: Charlie survives, Jack and Sara are still together. SG-1 did happen with same people, they did meet and ally with the Tok'ra, Martouf/Lantash is alive and with Sam