A blast (if somewhat underwhelming) blast from the past.
Cisco and Chester getting sent back in time was a great story line, due to the much needed character development Chester got. The references to the 90s was a great aspect to. I love Chester and Cisco's friendship so much, hope to see more of it.
The villain was very underwhelming. They need to start making these villains more of a threat very soon. I still hope Godspeed fights them in the near future.
The story line involving Nora and Iris was interesting to say the least. I get the feeling that something might be off with this Nora. While I am probably wrong, I am going to predict that this is Eobard Thawne/Reverse Flash in disguise. Again, I am probably wrong.
It was weird not having Barry in this episode, though it didn't affect it hardly.
Once again, Danielle Panabaker managed to steal the show as Caitlin Snow and Killer Frost. She is arguably the best actor on the Flash, and this episode just proves my point.
Out of a 10 I would give it...
7 out of 10