K.C. is finally coming to terms with no longer being a spy, but when a feared criminal escapes, the Coopers are given a chance to rejoin The Organization.
When a college student shows up claiming to be a relative, Kira is forced to tell a family secret she's been holding for years. Meanwhile, Marisa and Ernie give K.C. tips on how to handle her first date with Darrien.
Kira reluctantly agrees to help K.C. reunite Abby with her mother Erica, who has been hiding from The Other Side and The Organization for several years.
When Darien is mysteriously injured in an accident, K.C. tries to figure out who is behind it. Meanwhile, Craig becomes head of security for a vice-presidential candidate.
When K.C. learns Erica and Abby are working with the head of The Other Side to carry out an evil mission at the Presidential election party, the Coopers must act fast to stop the enemy agents.
Ernie tries to impress The Organization with his science skills and develops a truth serum. But things get out of hand when K.C. accidentally drinks it!
When K.C. has to find an undercover spy to pass a test for a promotion at The Organization, everyone at the Cooper's neighborhood potluck becomes a suspect. Meanwhile, Petey is on his own mission to try and scare Judy.
When K.C. has to capture wanted computer hacker.Noah Stone, she finds herself in competition with teen bounty hunter, Pinky Carter, who is also determined to take the hacker into custody.
When K.C. goes into a virtual reality game to rescue Ernie, it becomes the craziest Halloween ever for the teen spies as they try to tackle the alternate universe and enemy agents Darci and Damon, the masterminds behind the evil game.
The Coopers go undercover in a biker club to find Richard, the head of The Other Side. Meanwhile, everyone thinks K.C. is losing it when she claims to have seen her evil cousin Abby, the enemy agent she eliminated earlier on.