Stargate: Continuum is a Canadian-American science fiction film written by Brad Wright and directed by Martin Wood as the second sequel to Stargate SG-1, after Stargate: The Ark of Truth which follows SG-1 in their mission to re-instate the original timeline changed by Ba'al by infiltrating the ship, Achilles.
It is the second of two Stargate SG-1 direct-to-DVD films, the first one being Stargate: The Ark of Truth.
Continuum was released as a Region 1 DVD on 29 July, 2008 and first aired on television in the USA on the Sci-Fi channel on 3 April, 2009. It is 94 minutes long.
Stargate: Continuum aired for the first time in South Africa on TopTV's Fox FX channel on Thursday 19 July 2012, at 16h45.
SG-1 and Jack O'Neill (Richard Dean Anderson) attend a Tok'ra extraction ceremony for Ba'al (Cliff Simon), the last of the Goa'uld System Lords. He gloats that he is merely the last clone, and that the real Ba'al has a fail-safe plan.
The real Ba'al travels back in time to 1939 Earth and massacres the crew of the Achilles, the ship carrying the Stargate to the United States; the captain (Mitchell's grandfather) survives long enough to keep the ship from being destroyed.
In the present, people and objects disappear, starting with Vala Mal Doran (Claudia Black) and Teal'c (Christopher Judge). Jack is killed by Ba'al before Samantha Carter (Amanda Tapping), Daniel Jackson (Michael Shanks), and Cameron Mitchell (Ben Browder) manage to reach the Stargate.
Carter speculates that traveling through the wormhole shields them from the changing timeline. They emerge inside the derelict Achilles, which has drifted to the Arctic Ba'al's actions have created a timeline in which the Stargate Program never happened.
After escaping from the sinking Achilles, they are rescued by a team led by Colonel Jack O'Neill. Although General Hank Landry (Beau Bridges) believes their story, permission is denied to change the timeline.
In the alternate timeline Daniel is still trying to convince people about his theories of the pyramids, Carter died in a space shuttle accident and Mitchell does not exist at all because his grandfather died saving the Achilles from Ba'al's bomb. The three are separated and given new lives to lead.
A year passes, and SG-1 is called back into action when Goa'uld scoutships appear. Ba'al has defeated the System Lords and now stands ready to conquer Earth, with Qetesh (still residing in Vala's body) as his Queen and Teal'c as his First Prime.
SG-1 is brought to President Henry Hayes (William Devane) and General George Hammond (Don S. Davis), who inform them that, based on SG-1's accounts, they have recovered the Antarctic Stargate and are excavating the Ancient outpost.
SG-1 is sent in F-15s to McMurdo to gate to Proclarush Taonas, an Ancient outpost, to retrieve a Zero Point Module (ZPM) to power the Antarctic outpost. Above Earth, Ba'al's armada arrives. To the displeasure of his lieutenants (all former System Lords), Ba'al announces that he will treat the Tau'ri leniently.
Suspicious about Ba'al's knowledge of Earth, Qetesh betrays him and forces him to tell her everything. She has her ships destroy McMurdo Station and the Ancient outpost, and she kills Ba'al after Teal'c discovers her treachery.
As Teal'c escapes to an Al'kesh, Qetesh orders the fleet to bombard Earth while she goes to secure Ba'al's time machine.
Amidst the massive Goa'uld attack, SG-1 is rerouted to Russia, as the Russians had retrieved the Achilles' Stargate from the ocean floor. En route, they are saved from a flight of death gliders by Russian MiG 29s. Teal'c arrives at the facility as well, seeking to use the Stargate to reach the time machine before Qetesh.
The two sides form a truce and arrive together at Ba'al's time machine: a vast underground supercomputer connected to hundreds of satellites that monitor solar flares that could intersect the wormhole formed by the Stargate.
SG-1 must wait for the right flare with which to go to the past, but an attack by Qetesh's troops forces them to dial Earth in the year 1929 - ten years before their target date.
Sam and Daniel are killed in the firefight, and only Mitchell reaches the Stargate before Teal'c, mortally wounded, destroys the time machine along with himself and Qetesh.
After a decade of waiting, an older Mitchell stows away on the Achilles and kills Ba'al and his troops when they come through the Stargate.
In the present of the now-restored timeline, SG-1, completely unaware of the previous events, watch the extraction proceed without incident. On Earth, Daniel wonders what Ba'al meant by his fail-safe, but they decide not to dwell on it.
The final shot shows a close-up of a picture in Mitchell's locker, in which his older alternate self is shown standing alongside his grandfather.