Well, personally I didn't like it. But basically this is what it was.

Cameron was built as an infiltration unit to get inside John's camp to kill him. They built her to look just like one of John's trusted soldiers (Allison) who they had captured. Then they were questioning Allison in order to be believable as her if they were asked questions. So they could get past checkpoints. BUT the real way to pass was the bracelet which she lied about but Cameron ultimately found out about and killed Allison for.

Now, the weird part, and frankly the part I hated, was that when Cameron's chip malfunctioned again (seriously John it takes more than a q-tip to fix those things...try harder buddy) she blanks out on her current programming and is left with memories of the Allison incident. The problem is she thinks SHE'S Allison instead of the robot. And then she gets all emotional and weepy which is ridiculous because just cuz she had memories of that incident, she certainly doesnt feel emotions cuz she's still a machine, but whatever)

And about the end...I couldn't tell ya. The fact that Cameron, once she realized once again she was a machine and suddenly DIDN'T have emotions anymore even though she still had the memories, could go from "I want to stick John"s head on a spike" to "Come on John let's go home." defies all explanation and who the hell knows what happened there.

I like the episode a lot and I understood it completely.. :)

Okay, I get what happened to Alison, but how can a Terminator have memories of a human's life?