The Flash” has been racing towards a time-traveling climax all season, and the May 19 season finale promises to answer all our lingering questions about Eobard Thawne (Tom Cavanagh) and his vendetta against Barry Allen (Grant Gustin).

Cavanagh told Variety that he and Gustin had the exact same reaction to reading the finale script: “We were actually shooting, but Grant and I were sitting beside each other between scenes and he used an expletive followed by ‘Dude.’ And he just handed page seven over to me, and I’m like, ‘Expletive. Dude.’ I think that the ‘Flash’ writers’ room, and [Greg] Berlanti, [Andrew] Kreisberg, and [Geoff] Johns, have to be congratulated, because once you’ve crafted something over the course of 20 plus hours, there’s a lot that you have to deliver. You’ve earned a lot, but you don’t want to shoot sideways. We all know season finales that have been much anticipated and then don’t seem to hit the pinnacle. I’m not saying that we get to the top of the mountain, but if we don’t, it won’t be the writers’ fault. It will be us as actors.”

A new clip from the season finale, titled “Fast Enough,” sees Barry confronting his nemesis about why Eobard killed his mother, and the answer is simple.

Or is it?

“The way I’ve tried to play Wells is, you can play him as a straight villain, but it’s much more complicated than that, and it’s too simple to do that. It’s not interesting, given the layers that you could take advantage of to just play it that way. And all along, we’ve seen Wells has a vested interest in Barry’s improvement, at increasing his aptitude as The Flash, and his actual personal safety. And Wells’ interest in that is made clear as we step onboard the train of that last episode,” Cavanagh explained. “He’s always cared for Barry. He’s said as much. And in the end, in a strange twist, he is going back to save his mother and we know what the Reverse Flash’s involvement has been in that. And yet his greatest cheerleader in this enterprise is Eobard, for reasons that I won’t divulge — but it makes it that much more complicated … It’s not easy for [Eobard]; he doesn’t despise this version of Barry Allen. In fact, he cares very much for him.”

As for where the season finale leaves us, Cavanagh’s co-star Jesse L. Martin (Joe West) gave us a hint during a recent interview. “So many huge things happen in the episode and I’m not even sure what I can say. There’s so many surprises, but it’s definitely a cliffhanger. By the end of it, you have to imagine that things are just going to be crazy at the start of season two, because I believe that we’re starting season two directly after the last moment you see at the end of the season.”

Can Barry save his mother, and perhaps more importantly, should he? We’ll find out during the season one finale of “The Flash,” airing Tuesday, May 19 at 8 p.m. on The CW.