Not a bad episode at all, but this wasn’t a Flash episode, it was Crisis episode. As I stated in my Arrow, Season 8, Episode 1 review, I am worried that Crisis is taking over the plots of the stories. I understand that this is a huge, epic story and it’s been planned very well. If Crisis was the main plot, I would be happy with the episode. However, there is a scientist doing stuff behind the scenes, but really slowly! When Barry and the team will have a villain to fight, it may well be after Crisis, and that means a lot of filler episodes… many of which are dull.
Killer Frost’s storyline in this episode is nice. I did enjoy it and it was written well.
The radiation-wave-controlling twins or whatever were fun to have as side-plot of the episode, but it ended poorly. The Flash swooped in and saved the day. It would have been better to see our other characters, who had been developing around the plot, deal with the issue. That would have satisfied the story a little more.
Overall, it was a pretty good episode. I am excited for Crisis, but I want to see more of the standard stuff too!