Barry goes to the future to find out who Savitar is and finds out some unpleasant information while the gang deals with the fallout of what Julian did to Caitlin...
While we didn't get to see who Savitar is (BOO!!), Killer Frost did and she certainly seemed to know who he is, which leads me to suspect that Savitar is someone we know. One fairly obvious answer is Ronnie. When we last saw him, he was flying into the singularity, so he could have been trapped in the Speed Force for a long time or he could have been thrown out of time. And since the singularity was caused by Barry, that would certainly explain why Savitar has such a hatred for him. That being said, I am not sure how Ronnie could have become a speedster, unless the suit is what gives him his speed, so that is an issue. Based on what the future Killer Frost said to our Barry, the person who is Savitar is close to him, but since we saw the rest of the gang in the future, and we know that Savitar is trapped in the Speed Force, I am not sure who else it could be.
The future versions of everyone were pretty much what I would have expected. Having lost Iris, Barry seriously drifted from the group which led to the group completely falling apart. Joe is still grieving Iris' death, Wally tried to avenge Iris but ended up being paralyzed and in some sort of catatonic state, and Julian went back to science. About the only surprising thing was that Cisco had fought Killer Frost and she froze both his hands, so he lost them and had to create robotic ones for himself. Consequently, he lost his powers and everything else as well. Oh, and Killer Frost was captured and being held in the prison where Julian worked. And good old HR kept writing books (or a book anyway).
One thing that I did find interesting is that the city wasn't completely taken over by villains in the Flash's absence. You did have Top and Mirror Master who seemed to be on a bit of a crime spree, but that was it. I was pleasantly surprised that the writers didn't slip into that particular trope of a city going to hell in a handbasket with the absence of the hero, since that is something that could very easily have happened.
So the next thing for the gang to do is find the physicist who created the trap that Barry used to finally cage Savitar in the Speed Force and get her to create it early, because if they can, then Barry can save Iris. I'm not sure what the effects of changing the future that way will be, but I am not sure if things can get any worse for the group. But, as we know, messing with time is a dangerous thing, so trapping Savitar 4 years early could have unknown consequences. After all, that would mean saving at least one life (Iris), if not more, and who knows how people being alive who should have been dead will affect the timeline.
Until next week!