Another great episode.
I had two favorite little beats in this episode:
1) Carter and Jo talking in GD after the positron storm. Carter shows Jo deference as he's in her house, and she takes charge while showing deference to his position as her ex-boss. It was such a little thing, but it's something that would come naturally for them.
2) There were plenty of callbacks in the episode - Andy, Martha, and so on. The most subtle one, and my favorite, was Jack's line about collapsing space-time being bad. He would know, since he was/is the only one aware of it when it killed Stark.
I was very pleased that they got rid of the Bridge without making anyone a "bad guy," even if Grant, Fargo, and Allison all had excellent reasons to stay.
I'm assuming at this point that there was something between Kevin and Zoe. The way Allison said that they talked about girlfriends was way too coy, and Zoe's name-dropping was much too frequent.
Nit-picking about colleges: while Harvard is a good school, it's not really a science-oriented school, with the exception of the medical school. Even with the med school, I would expect Eureka's kids to be going to MIT or Cornell or similarly science-focused schools.
I like that Alternate Fargo was a dick. We also got hints that Alternate Allison may have been a bit distant with her kids. I hope we learn more about the other Alternate folks.
My day would be made if Stark shows up alive.