In this adventurous installment of the Stargate series, SG-1 and Jack O'Neill attend a ceremonial extraction of Ba'al, the last of the formidable Goa'uld System Lords. However, Ba'al claims that he is not the original but merely a clone, asserting that the real Ba'al has a cunning fail-safe plan.
Suddenly, the story takes a dramatic turn as the real Ba'al travels back in time to 1939 Earth. There, he carries out a ruthless massacre of the crew aboard the Achilles, the ship responsible for transporting the Stargate to the United States. The captain of the Achilles manages to survive long enough to unintentionally drop a bomb Ba'al left behind, preventing the ship's complete destruction. This act triggers a shocking ripple effect in the timeline.
In the present day, strange phenomena begin to occur: people and objects start vanishing, including Vala Mal Doran and Teal'c. During this chaos, Jack O'Neill is killed by the clone of Ba'al, leaving Samantha Carter, Daniel Jackson, and Cameron Mitchell to scramble for safety. They manage to reach the Stargate, only to be surprised when they emerge inside the derelict Achilles, which has drifted to the Arctic. Their actions have unintentionally created a completely altered timeline where the Stargate Program never existed.
Escaping from the sinking ship, the team is rescued by a military squad led by Colonel Jack O'Neill, who believes their story after extensive questioning by General Landry. Despite his belief, they are denied permission to attempt to change the altered timeline. In this alternate reality:
- Daniel is still trying to convince people about the significance of the pyramids,
- Carter died in a space shuttle accident,
- Mitchell does not exist at all, because his grandfather was the captain of the Achilles.
Separated and forced to lead separate lives, the trio is prohibited from having any contact with each other. A year passes, and the peace is disrupted when goa'uld scout ships arrive, signaling that Ba'al—who has now allied with other System Lords—has plans to conquer Earth.
Ba'al now bears the Queen Qetesh, whose body still hosts Vala Mal Doran, and has appointed Teal'c as his First Prime. The situation becomes even more precarious when SG-1 is called to brief President Henry Hayes and Lieutenant General George Hammond. They are informed that, based on SG-1's account in this altered timeline, the Antarctic Stargate has been recovered and is being excavated at an ancient outpost with the goal of reaching the powerful weapon that had previously saved Earth.
As Ba'al's armada arrives above Earth, he takes an unexpectedly lenient stance, surprising even his own subordinates. Suspicious about his knowledge of Earth, Qetesh betrays him, forcing him to reveal all he knows. She then orders the destruction of the Antarctic Stargate and the ancient outpost, but Ba'al is murdered by Teal'c when the traitorous Qetesh attempts to eliminate him.
In the chaos, she commands her fleet to bombard Earth and proceeds to secure Ba'al's time machine—an advanced supercomputer connected to satellites monitoring solar flares necessary for wormhole and time travel. When the Antarctic Stargate is destroyed, SG-1 is redirected to Russia, where the Russians have retrieved the Achilles' Stargate from the ocean floor. Teal'c joins them, seeking to use the Stargate to reach Ba'al's time machine before Qetesh can steal it.
The two groups agree temporarily to cooperate and eventually locate Ba'al's complex: an underground supercomputer network linked to numerous satellites that monitor stellar activity for wormhole activation. They must wait for the correct solar flare to trigger time travel, but chaos erupts when Qetesh's troops attack. Forced to dial the Stargate to 1929, a decade early, they lose Sam and Daniel in the firefight, leaving only Cameron Mitchell to pass through. The mortally wounded Teal'c sacrifices himself to blow up the enemy and Qetesh.
After a decade of waiting, Mitchell manages to infiltrate Ba'al's ship, the Achilles, and confronts him, ultimately killing Ba'al and his forces as they come through the Stargate.
In the restored timeline, SG-1 who are now unaware of the alternate events, watches the original extraction successfully take place without incident. Meanwhile, Daniel remains curious about Ba'al's mention of his fail-safe, pondering its true meaning in the aftermath of these events.
> Throughout this complex narrative, the characters grapple with the consequences of altering time and the enduring threat of the Goa'uld. The story blends action, suspense, and mystery as SG-1 fights to protect Earth from ultimate destruction, even as they face the possibility that some changes to the past could have irreversible effects.
