CTU apprehends a suspect in the thickening assassination plot, but Chloe's convinced they've got the wrong person. Meanwhile, Dana's past returns to haunt her.
Jack becomes further involved in preventing the assassination attempt. Meanwhile, tension simmers when Dana is reunited with a familiar face from her past.
In the fallout from the attack, links are made to a Russian cell, and an irrevocably changed Renee resurfaces. Then, Hassan's betrayer meets with his allies.
Jack reteams with Renee to chase dangerous leads. Then, President Taylor learns of a looming threat that seriously jeopardises the peace accord with Hassan.
Jack is set up, Renee makes a sacrifice, Dana sends her ex into a police warehouse, an arms trader deals with his sons, and the President buys time.
