Moebius, Part 1

Plot
Carter reveals the existence of the Daedalus: a new Earth-built battlecruiser which is capable of reaching the Pegasus Galaxy and is larger and more advanced than the Prometheus.

Later, Daniel Jackson learns of Catherine Langford's death and, after her funeral, receives Catherine's collection of documents and artifacts relating to the Stargate program. From one book in the collection, Daniel learns of the former location of a Zero Point Module in Ancient Egypt. Dr Jackson and Colonel Carter persuade General O'Neill to use the time travel capabilities of the Puddle Jumper they found to travel back and take the ZPM, assuming that Ra never knew of its purpose.

Once they arrive in 3000 B.C., they join in an offering to Ra and witness his brutal murder of an Egyptian making the offering. Teal'c disguises himself as a Horus Jaffa and retrieves the ZPM from Ra's treasury. However, Ra's Jaffa discover the cloaked Jumper after a sandstorm covers it in sand. Unwilling to upset the future by fighting the Jaffa to get the Jumper back, SG-1 decides to live out the rest of their lives in the past, knowing that the rebellion that overthrew Ra will eventually happen. However, an alternate timeline is created in which the Stargate was never discovered and everything SG-1 have done for the last eight years never happened.

In this timeline, Alternate-Daniel is teaching English as a second language, Alternate-Carter spends her time double-checking other scientists' work, Alternate-O'Neill is retired from the military and Alternate-Teal'c is still the First Prime of Apophis. Alternate-Daniel and Alternate-Carter are contacted by the Air Force and brought to Cheyenne Mountain.

At Cheyenne Mountain, General Hammond informs Alternate-Carter and Alternate-Daniel that archaeologists found a video camera in a vacuum-sealed canopic jar at a dig in Giza. The video contains a recording of the original SG-1, explaining who they are and what they were doing, as well as a number of things that are true in their timeline, such as recent political events, Presidents and personal details. Their plan is that if things have changed in the future, then SG-1's alternative selves will travel back in time and fix the past.

An expedition team is sent to find the Giza Stargate, but find nothing. Instead, they discover that the original Daniel left a tablet where the gate should have been, inscribed with an obscure dialect of Egyptian that only Alternate-Daniel can read. It reveals that the original SG-1 instigated a successful rebellion against the Ra of 3000 BC. However, this caused him to leave Earth with the Stargate. However, they do find the Puddle Jumper, and Alternate-Daniel and Alternate-Carter figure out how to find the Antarctic Stargate. A team is assembled to go through the Stargate to recruit Alternate-Teal'c under the instruction of the Daniel and Carter on the tape. Alternate-Daniel and Alternate-Carter are not going to be on this team.