Ep 4. Allison from Palmdale

In Terminator: The Sarah Connor Chronicles season 2 episode 4, titled "Allison from Palmdale," the story revolves around Cameron's mysterious behavior and her past. The episode begins with Cameron completing a mission, and John and Sarah Connor wondering why she has been acting so strangely lately. John starts to investigate and finds out that Cameron had been trying to contact a fellow cyborg named Allison Young.

Meanwhile, the episode flashes back to 2007 when a terminator named Cromartie captures a woman named Allison Young. He interrogates her in a garage, demanding to know everything about Connor and the resistance. Suddenly, a second terminator – one that looks exactly like Allison – arrives and engages in a fight with Cromartie. During the scuffle, Allison escapes and the two terminators disappear.

The episode later returns to present day, and Cameron eventually tells John that she and Allison were built in the same factory and were essentially sisters. Cameron also reveals that Allison was sent back in time to protect John Connor, but when they were cornered by Cromartie, Allison was captured. Cameron herself was also captured, but she managed to reprogram herself to help protect John.

As the episode progresses, Cameron reveals to John and Sarah that Cromartie's goal was not to kill them, but to capture them and bring them to a place called Zeira Corp. Cameron believes that the company is working on advanced technology that could be a threat to their mission to save humanity, and therefore sets out to investigate.

"Allison from Palmdale" is a thrilling episode that sheds light on Cameron's past and the motives of the terminators. The episode also explores the concept of sisterhood and the bond that can form between machines. The flashbacks and character development add depth to the storyline, and the action scenes are intense and well-executed. Overall, this episode serves as a key component in the ongoing story of the Connor family and their battle against Skynet.