Agent Kara is a CIA agent, specializing in miniaturation projects with Stan in "Frantastic Voyage".
When Francine makes a friendship with her at a CIA party, Stan later claims that Kara found her insufferable. When Francine shows up at the miniaturation lab to make amends, Stan hurriedly injects the miniaturized Kara into himself, claiming that she had been transferred. He later explains to deputy director Avery Bullock that Francine always hijacks his friendships. Singing to herself that night, Francine realizes that Stan is also sharing the melody and a closer examination reveals Kara manipulating his vocal cords. When she apologizes, she discovers that Stan lied to her and Kara needs to get out quickly, although Stan refuses to stir from his sleep. Searching for a bucket of liquid to wake Stan up, she finds out from Klaus that he has repeatedly hidden his friends from her.
Francine hauls him down to the CIA headquarters and enlists Bullock's help in shrinking herself down. Inside, she finds herself attacked by white blood cells, but is saved by Kara. As she talks things over with Kara, Stan has woken up and is upset with Francine. She refuses his orders to leave immediately, revealing that she's already with Kara. Stan attempts to force them out without success, but when they discover that his brain is full of spiders and come under attack, they have to bail out of Kara's ship and call for help. When he realizes that his first idea of shrinking himself down and injecting himself back into himself won't work, he realizes that the people he needs to complete the mission are the ones that he had hidden from Francine all this time. Despite the death of one of their members, and heavy attacks by the spiders, they succeed in recovering Kara and Francine, along with a baby spider who snuck onto their ship.