The Flash Stars Preview Episode 100's Chill-Inducing Trip Through the Past

The Flash Spoilers

For its 100th episode, The Flash is taking a very special father-daughter trip through time: one full of tears, chills and uncomfortable truths.

In order to defeat Cicada in the present, Barry and Nora travel back to memorable moments from the show’s five-year run in Tuesday’s installment (The CW, 8/7c), with the intent of gathering some key tools. During the journey, “with the exception of DeVoe, we see every Big Bad, which is pretty cool,” star Grant Gustin previews. “We do it in a way we’ve never done before with time travel, where it’s all kind of like those Back to the Future moments where they’re in the parking lot and they see Doc Brown get shot again.”

Among the foes making a return are Zoom, Savitar and Season 1 Big Bad Eobard Thawne, as revealed in a promo. In revisiting her father’s history with these villains, Nora “finds out things about her dad that she certainly didn’t know because they weren’t in the Flash museum,” Jessica Parker Kennedy shares, “and things that she doesn’t necessarily like about her father, stuff that’s made her very uncomfortable — which is important. To get to know someone, you have to know the good about them and the bad about them as well.” Ultimately, the revealing time-trip brings father and daughter “a little closer,” Gustin says.

For Kennedy, who only recently joined the ensemble, being invited along for the milestone ride was an honor she wasn’t expecting. “I didn’t think I was even going to be able to be such a big part of the 100th episode,” the actress confesses. “I thought it would be much more [about] the other characters. So I feel it was such a blessing… to be able to go to the other seasons and be there in this strangely real way.”

Behind the scenes, the episode also had a family affair feel: The hour was directed by longtime series regular Tom Cavanagh, who raves about Gustin’s ability to make “difficult things look easy.”

“There’s a moment — and you’ll know it when you see it — when everything is going to hell” for Barry and Nora, Cavanagh describes. “Everything is just falling apart.” Amid the chaos is “probably the most significant father-daughter moment that we’ve done this season,” and it’s one that packs an emotional punch.

“I’ve watched, in the edit [process], people who run our show moved to tears by the acting of [Grant] and Jessica Parker Kennedy [during] this moment,” Cavanagh says. “And the great thing about it is there’s barely a word spoken.”

So we’ve got waterworks covered. But what about “OMG!” surprises? “There are some shots in there that just are going to send chills up people’s spines in the best way,” Hartley Sawyer, who plays Ralph Dibny, teases.