K.C. and her family are back with a new mission: rejoin The Organization! When a long-lost cousin unexpectedly shows up, the Coopers must decide if they can trust her with their spy secret. Kira and Craig discover the preacher who married them was actually an agent for The Other Side, so the kids decide to throw them a do-over wedding. And when Ernie concocts a truth serum, K.C. finds herself in hot water after she accidentally drinks it! No matter the danger, K.C. will complete the mission with a little help from the greatest team a spy could ask for - her family!