As “The Flash” speeds toward its season one finale on May 19, secrets are finally being revealed; last week’s episode ended with the Reverse Flash — aka Eobard Thawne, aka Harrison Wells (Tom Cavanagh) — kidnapping Eddie Thawne (Rick Cosnett), for reasons that have yet to be uncovered. Meanwhile, Eddie’s girlfriend Iris West (Candice Patton) finally figured out the secret identity of Barry Allen (Grant Gustin) as the Flash, which should lead to a painful confrontation between Barry, Iris and her father, Joe (Jesse L. Martin), once she realizes that the men in her life have been lying to her for months.

Ahead of the May 5 episode, “Grodd Lives,” Variety spoke to Jesse L. Martin about Joe’s relationship with Iris, his confrontation with Grodd and what’s ahead in the “huge” season one finale. Light spoilers ahead.

Last week’s episode saw Eddie being kidnapped by the Reverse Flash — what’s Joe’s reaction when he discovers that Eddie is missing?

That is the most devastating news; I keep losing partners to these meta-humans. So we don’t know what he’s planning to do with Eddie, but we do know that there’s some connection between their names, the Thawne name. So we’re not sure what he could possibly be doing with Eddie or why he would kidnap Eddie, but it seems quite dangerous that it’s occurred, and it’s all about finding Eddie at that point. It definitely can’t be good.

This week’s episode also reintroduces Gorilla Grodd — what was it like to shoot those scenes?

It was actually quite amazing. This is one of those shows where you end up acting to almost nothing sometimes — maybe an X taped on the wall, or on a stick, or what have you — but just seeing what the renderings were for Grodd and how fantastically huge he is and obviously bigger than life, it’s pretty easy to imagine how horrifying that would be. Joe is particularly horrified by normal gorillas, let alone a supernatural one… It’s ultra-realistic and a lot scarier than I ever imagined it would be.

Viewers might have some idea why Grodd is on a rampage, given his history with General Wade Eiling (Clancy Brown), but how much does Team Flash know about his motivations in the episode?

We don’t even know what Grodd’s motivations are right now other than that he may have been treated very poorly by someone, and we’re not exactly sure who that is. Barry has flashes of the treatment that Grodd received, because Grodd’s sort of telepathic, so he shoots some of those images to Barry. So Barry has an idea of what happened to Grodd. We don’t know who did it and why Grodd would be on a rampage.

Like any good parent, Joe always manages to justify keeping secrets from his kids under the guise of protecting them, but now Iris knows the truth about Barry — what can you say about the repercussions of him hiding that from her, once she finds out that Joe was in on it?

Well, it’s one thing to hide something from Barry. Barry has his own way of reacting to those things, but Iris is a whole other story. I liken her to her mom [who we don’t even] know yet, but I’m imagining that she would get that from her mom where it is devastating to her to be left out, to not know what’s really going on. And when she finds out by herself, she feels betrayed by both me and Barry, and rightly so. But again, Joe is right at least in his own mind that she shouldn’t know these things until needs be, because it’s probably safer that she didn’t know.

Is it really, though? She has still ended up being targeted by a number of villains despite not knowing the truth…

I think it had been… Iris is a very inquisitive girl. There’s a reason she’s a journalist. So if she finds out, she has a way of doing things without saying so, like reporting things without coming to us and saying, “Is it cool that I report this?” So that’s a good reason to keep that information from her, at least temporarily. [Laughs.] But I understand the conflict because we are talking about my flesh and blood, my daughter. So she’s right in a way when she says, “Don’t you think it would’ve been safer for me to know so I could protect myself?” But to me she’s always my little girl so I’m going to treat her that way on instinct.

In episode 22, “Rogue Air,” the synopsis reveals that Barry turns to Captain Cold (Wentworth Miller) for help against Wells, which Joe obviously can’t be thrilled about. Does that mean we’re going to get an “I told you so” moment when things inevitably go awry?

I imagine that that is the case. [Laughs.] It’s not necessarily an “I told you so moment,” but it is brought up and Barry pretty much says “thank you for not saying it.” So it is approached, but I never actually have to say those words. But Barry gets in bed basically with one of the super villains and that can never go well. We’re learning that with Harrison Wells. We don’t even know Captain Cold that well. So the fact that Barry’s so desperate for help that he would go to somebody like that just sticks in Joe’s craw like you wouldn’t believe.

How much of a role does time-travel play in the final few episodes, beyond what we’ve already seen of Wells coming back to the past?

We do approach the notion of time travel, and Barry’s presented with a chance to save his mom, and the big dilemma is, if you go back in time and you change one little thing, of course that affects everything going forward, and he realizes that he may not have the life that he had growing up with us if he goes back. So there’s a huge dilemma as to whether it should happen or not, and of course, he turns to Joe and asks for advice. Joe’s notion is that if he can make things right then he should. So the entire episode for the audience will be about whether or not Barry actually goes back and changes history.

What can you preview about the potential repercussions of the finale and how it’ll affect the show’s trajectory going into season two? Are we heading for a cliffhanger?

Absolutely. Yes, it is. So many huge things happen in that 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.

The pace of this season has been staggering — there have already been so many plot twists and reveals, I can’t imagine how you’ll top yourselves in the finale.

I have to say, it’s one of the luckiest jobs I’ve had. I mean, luck is a funny word because I did work very hard, but just being in the situation where I actually get to work with these people every single day and the stuff we get to do because of the genre, it’s awesome. It’s like an actor’s playground.

“The Flash” airs Tuesdays at 8 p.m. on The CW.