I watched the first half of this episode right before bed last night, half asleep already, and I had to watch the whole thing over again this morning to decipher the three time periods of the episode and the slowly crumbling divide between what objectively happened and what was going on in Reese's head.
It was a framework we've seen before on plenty of other shows, but it was a more awkward fit here where the framing device of the Machine usually keeps things so orderly and regimented that we not only know something objectively happened but we know exactly when it happened. The dramatic scaling back of that framing device threw me off kilter as much as anything else.
All of that being said, I'm glad they brought Taraji P. Henson back for this episode because the forced romantic angle between Reese and Carter in the episode where Carter was shot to death never sat right with me. This episode left their relationship at the right place: a very deep friendship between two people with important touchstones of common biographical experience. In those final scenes, where Henson was playing the angel of death as much as she was Carter, she just knocked it out of the park.