Carter is concerned when Zoe takes a part-time job at Cafe Diem but bigger worries await. Henry Deacon may face a long jail term for the breach of security that saved Kevin. Nathan Stark proposes to Allison Blake. Zane Donovan, Fargo and Larry are preparing for an anti-missile test and the Department of Defense sends in Eva Thorne, a ruthless corporate fixer, to conduct a performance review of Global.
The Viper test should be swift and simple. Several target drones, developed by Dr. Ethan Edison, will attack and the Viper will shoot them all down. It happens every time. The real source of tension at Global is Thorne. Only Larry, always currying favor, is happy to meet her.
The test begins and all the drones go down but one. It survives the attack; fires back, then cruises off into the sunset. None of the fail-safes can correct its course. Capturing it becomes Carter's assignment.
He consults Dr. Edison who is baffled by his creation's success. "Martha" is a learning computer and she appears to be learning too fast. She should be a toddler but she is acting like a teenager. He worries about what she will do if she feels threatened. What she does is chase Carter into the Sheriff's office and promptly become invisible. Carter and Jo manage to corral her in the jail cell but their triumph is short-lived, as is the cell's back wall.
Carter and Allison go to Edison's lab and meet his wife Mina, who is about to celebrate his success. Edison tells them that he did not give Martha the ability to cloak because it draws too much power; she will have to return to his lab to recharge. She is lurking nearby and sees Thorne, Stark and several others from Global confiscate Edison's remaining drones.
Martha and Zoe share a teenage moment in Vincent's fusion-powered freezer before Martha liberates her fellow drones and leads them skyward. Thorne scrambles the fighter jets and, as Carter, Stark and Allison advocate tough love, the jets close in for a deadly confrontation in the skies over Eureka.