Cause and Effect plays with a familiar storyline in superhero lore, the titular character losing their abilities. But it provides for a surprising number of great character interactions among the STAR Labs crew.
After finally revealing who Savitar actually is, a future version of Barry himself, we are now left with how to deal with the god-like speedster. Interestingly enough, since Savitar and Barry Allen are one in the same, this is what allowed him to always be one step ahead of Barry and the STAR Labs crew. But, Cisco and Julian come up with a fantastic plan; in typical CW fashion, things go horribly awry.
Cisco and Julian attempt to temporarily inhibit Barry’s short term memory, so they can craft a plan to take down Savitar. But, they accidentally affect Barry’s entire memory. He doesn’t know who anyone around him is; he doesn’t even know his own name.

While there are certainly negative side-effects to Barry’s temporary condition, such as allowing a pyromaniac to go free due to his testimony on the stand, the one character that actually favored his current aloofness was Iris West.
The episode did a great job of showcasing what could be in a world where Barry Allen doesn’t carry the weight of Central City and just as notably, Iris West’s current predicament on his shoulders. It really brought back the memories from early on in Season 1 when Barry wasn’t yet aware of the emotional toll in which being The Flash would take on his relationships. The fact that he has seen Iris’ death by the hands of Savitar over and over again certainly provides little levity to the situation. Iris even plays with the situation of believing that maybe this is better for Barry and everyone involved. It’s that tempting feeling of finding comfort in the “what ifs†in life which made the sequences where Barry didn’t have his memory so strong.
Touching on the subject of relishing in the past, Cisco and Julian get to have the most meaningful interactions with Caitlin Snow sincer her Killer Frost transformation.

Since Savitar has also lost his memories, Caitlin proposed to help the team return Barry’s and thus Savitar’s memories so that she can use him to reverse her transformation. The scenes where the three were working in the lab to come up with a cure for Barry’s memory loss provide a touching trip down memory lane. The way Cisco walked her through her most pivotal relationships, such as her marriage with Ronnie and her various times with Cisco was a nice touch that allowed us to see that there is indeed a little part of Caitlin still alive within Killer Frost.
To my surprise, we were also given a great handful of scenes with Tracy, who was introduced in the prior episode, with HR. Tracy is still tasked with creating a barrier to trap Savitar, and the stress of the situation is slowing her progress. HR swoops in to help the team out, and himself of course. The cutesy flirtation back and forth between the two finally boiled over here, and there were some awkward romantic scenes between the two. I know there will be a handful of people who don’t like the very CW drama, but it was a nice contrast between Barry’s memory loss scenes.