Cassandra Railey goes back to 2020 on a mission to kill Dr. Katarina Jones. Followed by James Cole to stop her from this mission, they find themselves stuck in a time loop.
After the tragic events of the meltdown, Jones is left with the disheartening realization that humanity's true enemy is time-travel itself. As its architect, she elects to do the unthinkable - send Railly back in time to 2020, to kill Jones while she was still at Spearhead in order to undo all of it. However, Cole and Railly discover a shocking anomaly in their quest to carry out Jones's wishes