With the previous ending with Cisco's (not entirely accurate) revelation that Jay Garrick, the man who they had all grown to trust, had actually been Zoom all along, Barry seems to be more committed than even to finding some way to improve his speed. Despite his best efforts, though, it seems that no amount of research will allow him to find a way to close the significant gap between his own speed and that of the other speedster he had encountered.
After witnessing what had happened to Trajectory, in the previous episode, Barry has come to accept that Velocity-9 simply isn't an option – but, he is clearly running out of idea. But, of course, inspiration often seems to come from the strangest places – so, it feels oddly fitting that an almost entirely unrelated conversation with Wally West will be the catalyst that allows Barry to come up with a new plan of action.
It is, as a said, an outlandish and risky plan. Despite this, though, the only true objections are raised by Earth-2's Harrison Wells, who clearly has issues of his own with his daughter's recent decision to leave so soon after being rescued – and, so, Barry goes ahead with some degree of confidence.
But, of course, things begin to go spectacularly wrong almost immediately. After a close encounter with something unnatural in the time-stream, Barry emerges to realise that he has travelled a little too far. Then, his efforts to incapacitate his past self are momentarily complicated when the younger Barry has the chance to fight back. And, on top of that, Barry's efforts to subtly lead Thawne to helping him with his current issues are complicated when the strange creature that Barry encountered while travelling backward through time emerges – its focus now firmly fixed on Barry. Then, to complicated matters even further, the fact that Eobard Thawne is able to recognise this strange entity as a 'Time Wraith', a constant danger to speedsters who travel through time, provides him with the final clue to determine the Barry Allen who is suddenly asking him so many interesting questions might not be the same as the one he knows.
As a story that dives head-first into the occasionally baffling complexities of time-travel, this episode would have to rate as one of the most purely fun of the season, so far. Barry's encounters with his younger self, both the brief struggle that takes place when they first meet and the amusing moment when they cross paths again later, were very entertaining – with Grant Gustin doing an impressive job of showing the subtle changes that another year of experience has had. On a similar note, Cisco's confused efforts to determined which 'Barry Allen' was the real 'Barry Allen' would have to count as one of the episode's best moments.
It was also great to see some older characters have the opportunity to return. With Hartley Rathaway/Pied Piper (Andy Mientus) being one of the more interesting 'one-off' villains to appear during the first season of The Flash, it was great to see him brought back in such an interesting, and unexpected, way – and, it was especially interesting to see him shift from villain to potential ally when the events of the past are altered by the presence of the Time Wraith. Perhaps most importantly, though, it was also great to see Eddie Thawne (Rick Cosnett), again – even if his appearance in this episode was more circumstantial than necessary.
The episode's true high-light, though, would probably have to come from giving Tom Cavanagh a chance to return to the character he had played throughout the first season. The fact that, on top of everything else, we also had Eobard Thawne/Harrison Wells and Earth-2 Harrison Wells appearing in a single episode was fantastic – as well as a great show-case of exactly how impressive a job Tom Cavanagh has done of distinguishing the two.
Eobard Thawne being portrayed as intelligent enough to realise that he was dealing with a future version of Barry Allen was also a very entertaining development – and, the way that he gradually came to realise that Barry's presence, here, meant that his plan must have failed in the future added a very genuine element of tension, while it lasted. I do have to admit, though, that I wasn't convinced by the way that Barry was able to trick Wells, here – with Barry concocting a quick lie about Thawne ultimately winning in the future. I suppose that can be attributed to it simply being a lie that Eobard Thawne wanted to believe, though.
The Time Wraith, itself, was also a very interesting new element, here – although, with so many questions still unanswered, it's probably just as likely to be a source of frustration for some members of the audience. Assuming that this isn't actually going to be the last time we see any of these strange creatures, though, I am looking forward to learning more about them, and they role that they seem to play (such as, for example, why the Time Wraith clearly seemed to be wearing a mask, much like the Flash's own, during close-up scenes). But, for now, I suppose I'm willing to wait for the answers I want.
Some of the episode's other elements weren't entirely successful, though. For one thing, it seems to have becoming something of a depressing trend, lately, for Wally West to appear in only a single scene, if he appears at all, and for him to have nothing much to do. That's bound to change eventually, though – I just hope it doesn't take too much longer.
Also, the potential of a new relationship for Iris West, with her new Editor, doesn't strike me as especially interesting. But, at least here, it was able to tie back to Eddie's brief appearance in an interesting way. The fact that Barry would find the time, while in the past, to have Eddie record a message for Iris, under the pretense of it being a birthday present, was genuinely touching – and, the video message, itself, was great. It's really just kind of a shame that Eddie Thawne couldn't have had a bigger role to play, in this episode.
With this episode ending with the clear indication that Barry's journey into the past actually has had unintended consequences, I can only hope that this might be something explored in more detail throughout the rest of the season – because, otherwise, it could all end up seeming a little too easy. Either way, though, this episode was still a great reminder of exactly how much fun The Flash can be – so, it deserves a fair amount of praise, just for that.