Kids. We get a much-needed break from the Ori and the Priors, and the kid isn’t happy with it. I think it’s just terrific. “Collateral Damage” seems to have been inspired by the 2004 film Eternal Sunshine of the Spotless Mind. It’s about a society which has uncovered some very old tech and built a machine around it that can erase or add memories. Amusingly, the machine is very clearly the same prop that was used two seasons previously in the episode “Revisions”. The story is a murder mystery of sorts, with Mitchell waking up in the apartment of a murdered scientist and the memory that it was he who killed her. There aren’t too many suspects, though one of them is guest star William Atherton, but there’s a very good twist to the whodunit and an even better one when this society decides what to do with him. Shame the kid didn’t enjoy it, but I certainly did.