When Flash came back for season eight, they started off with a five-part crossover event, Armageddon. Then they went on hiatus for a while. Now returned, the focus actually shifts away from the main characters. Barry and Iris’ kids from the future, Bart/Impulse and Nora/XS take the lead as they find, as their father before them, that time travel can be very complicated. There are a lot of paradox issues and shifts in the timeline, as well as the return of a favorite character (of mine, at least) and the introduction of an intriguing new one. We also get to see some interesting contrasts between the brother and sister here as we explore “Impulsive Excessive Disorder.”

XS and Impulse, in the comics, are from a lot further in the future. Their home is the 30^th/31^st century, where XS is a member of the Legion of Super Heroes. They’re also a generation removed, as they are the children of the Tornado Twins, who were the actual children of Barry (the Flash) Allen and Iris West, also making them cousins, not siblings. But I can certainly understand trying to streamline all that. Comic book history is complicated, and doesn’t always translate well into live action or ongoing tv shows. In her original incarnation, XS’ name was Jenni Ognats, not Nora West-Allen.

The actual episode kicks off six months ago, as Barry and Iris renew their vows in a nice family event. Bart and Nora were happy to be there, but returned to their own time in 2049 to try and minimize the chances of messing with the timeline. Nice thought. The two apparently share an apartment, as they get home and check things out, finding no immediately obvious changes in history. Didn’t XS used to have a Gideon AI in her gauntlet? Or was that the first one, since this is technically XS 2.0? At any rate, they just barely have time to refer to some emotionally important things they saw in the past before a green wave of energy washes over everything and makes some changes. I guess green is the time travel color of the Arrowverse, since it seems to be the background of the Temporal Zone on Legends as well as the energy signature for Deon the Still Force/time manipulator. At any rate, they know things are different, and then proof walks in the door.

Nora and Bart hurriedly confer on the changes they’ve found, slip in a nod to the Young Justice cartoon, and then find even more shifts in history than they were first aware of. The siblings adjourn to the Flash Museum, and visit the Hall of Heroes, where there are some familiar items on the walls. Consulting a history exhibit, they pinpoint some changes and realize that, in that particular year, it’s up to them to fix it. This happens arguably before the Arrowverse proper has started.

Relocating to New Year’s Eve of 2013, the siblings see an early interaction between Joe West and Cecile Horton, which doesn’t go well. Amusingly, Bart is dressed very much like Barry Allen used to when he first appeared, back in 1956. They also run into Eddie Thawne, who we haven’t seen since early in the Flash’s run, and cough up a cover story. They even have fake ID’s to go with their story, although those should have the wrong dates on them if they are what’s been used before. Unfortunately, their cover identities don’t exactly command respect, and they end up getting sent for coffee. But, it’s an important errand for two reasons. They meet Avery, who is more than likely a version of the Flash from the Justice League of China (based on appearance and same first name), and it’s the first time in Flash history someone goes out for coffee and doesn’t go to Jitters. Nora finally manages to get her younger brother back on track, and they see the event they’ve come to “fix” Unfortunately, Impulse lives up to his name, making things more complicated, and then they both screw up and allow themselves to be overheard. Talking about secrets in public is a long-standing, and amazingly foolish, tradition throughout the Arrowverse.

Nora takes Bart to task, which he earned, and tries to impress on him the need to be more careful. I guess if she succeeds, he’ll need a new codename. They have another encounter with Eddie, which doesn’t go at all their way, and they have to come up with a new idea to see what else has gone wrong. Elsewhere, some vaguely familiar people meet up at a bar and we see the birth of an ongoing annoyance in the Arrowverse, not that they’re much better in DC Comics. It’s a weird little meeting with at least one highly improbable prop.

Nora and Bart manage to more or less keep a low profile, achieve their objective, and even give Joe some good advice in passing. They visit a very important place in Flash history, figure out the newest anomaly, and Bart feels the weight of what he’s done crash down on him and takes off. Nora finds him later at another important spot to Arrowverse history, and she gives him a reassuring talk. The kid really is kind of high strung. Arriving at a new conclusion, they race off to meet up with a new consultant and have a very amusing exchange before finally getting their help. But the ripples are already spreading from some changes they’ve made, and a new menace shows up to complicate things. There’s high-speed hijinks, an interesting showdown, a brief undercover identity, and a really badly done bomb disposal scene. I’ll just say that if you need to get rid of multiple explosive devices, a nice big harbor is probably a better idea than tossing them into the sky and just kinda hoping they don’t hit anything important.

They do a lot of fun fan nostalgia bits back in 2013, including hope for Joe’s love life, a first meeting we’d only heard about, and a wish for the coming year which is doomed from the moment it’s uttered. Bart and Nora talk about going home, but are very slow off the mark for speedsters. They get dragged into something else that could be a bit of a paradox before they manage to get clear. Bart goes back to revisit someone he’s been enjoying spending time with and then the speedster siblings go home. Finally. What they find out is that, to borrow the Legends’ catch phrase for a time, they didn’t fix the timeline exactly but “screwed things up for the better.” They get in a few amusing lines with a returned person who is very important to them, and even a possible explanation for something we saw on another show. However, because things can’t be simple, the episode ends with a scene that seems to indicate all is not well in the present.

What I liked: There were a lot of nice nods to various bits of Arrowverse and DC Comics history, from how Bart was dressed to a nod to the Golden Age, and the early stages of a few important relationships. Both the main characters did some foolish things, but they really had each others’ backs, and it was reminiscent of, though not quite as good as, the brothers in Superman and Lois. I was amused that Bart’s attempt at undercover work didn’t extend to his footwear. It was nice to see Eddie again.

What I didn’t: There were a lot of weird little moments that didn’t quite work. Throwing the bombs in the air, being reckless with history, causing time ripples while trying to fix things, Eddie’s inconsistent coffee order; there were a lot of moments of weird writing choices, even with this being a fun episode.

Despite a few flaws along the way, it was a fun and entertaining episode. I’ll give it a high 3.5 out of 5. It’ll be interesting to see where they go from here.