Warning: spoilers ahead for Episode 16 of The Flash Season 3, "Into the Speed Force."
Barry zipped his way back into the Speed Force in "Into the Speed Force," and it was a much scarier experience this time around than it was back in Season 2. Still, Barry wouldn't be scared out of the Speed Force, as he was determined to retrieve Wally after Savitar snagged him out of Central City last week to take his place in the Speed Force. Barry discovered that Wally was stuck in a temporal loop that was forcing him to relive the single most painful moment of his life over and over again, which... pretty much explains why Savitar hates Barry so much.
Barry had to face off against Speed Force versions of his dead pals in the form of Eddie Thawne, Ronnie Raymond, and Leonard Snart before he found Wally and learned the terrible truth of the temporal loop. Unfortunately, Barry didn't seem to connect the dots between the terrible thing happening to Wally and the terrible thing that was happening to Savitar the whole time he was trapped in the Speed Force. We don't know just yet who the man is beneath the Savitar armor (although you can check out our list of the most likely candidates), so we can't say just yet what painful memory he was reliving, but we can bet that it was pretty damn awful.
Just because he's a supervillain doesn't mean that he can't have a tragic backstory! Obviously, I'm not arguing that Savitar is justified in killing Iris in the flashforward, because that remains one of the most horrifying scenes ever to air on The Flash to date. His sentencing to the temporal loop in the Speed Force does explain his motivation, however. He's not just going after the Good Guy because he's a Very Bad Guy; Savitar is going after Barry in such a deeply personal way because Barry subjected him to reliving his most awful memory over and over again.
Of course, we can probably excuse Barry for not immediately connecting the dots between what happened to Wally and what it must have meant for Savitar during his much longer time trapped in the temporal loop. Barry was distracted by the fact that Jay Garrick came to their rescue in the Speed Force... and then stayed behind to take the place of the stuck speedster so that Barry could save Iris. Poor Jay now faces the depressing prospect of reliving his own personal hell for however long it takes Barry and Co. to defeat Savitar and find a way to free him from the Speed Force without another speedster needing to take his place.
Personally, I'm curious to learn if the temporal loop has something to do with the origin of the man beneath the Savitar armor. "Into the Speed Force" finally clarified that Savitar is indeed a human in a suit of armor. If The Flash uses some of its classic time travel shenanigans, it could easily turn future Wally or Jay into Savitar and argue that they were so traumatized by their time in the temporal loop that they eventually went mad and were consumed by the need for revenge on the speedster who kinda sorta got them stuck there.
Grant Gustin did just say that we won't find out Savitar's identity the same way we did for Reverse Flash and Zoom, so I'd say that it's very possible that the temporal loop will cause more damage than what we just saw in "Into the Speed Force." Tune in to The CW on Tuesdays at 8 p.m. ET to catch new episodes of The Flash. Next week marks the big musical crossover between Supergirl and The Flash, so be sure to mark your calendar. Don't forget to take a look at our midseason TV premiere schedule to see all your other viewing options.