Sandra Bullock and Daniel Radcliffe Dish on Channing Tatum and Brad Pitt's 'Lost City' Wigs (Exclusive)

The pair opened up to ET about some of the crazier moments from the action rom-com.

Sandra Bullock's forthcoming action-adventure rom-com The Lost City has some spectacular stunts and even more exciting cameos -- and the actress is opening up about how some of the movie's most memorable moments came to be.

Bullock and co-star Daniel Radcliffe recently sat down with ET's Cassie DiLaura, and they reflected on some of the movie's most exciting scenes -- including a daring rescue by Brad Pitt that featured an enormous explosion.

"We only did that shot in one take!" Bullock revealed. "We didn't know how big the explosion was gonna be. It's all about preparation, preparation, preparation and then a whole lot of luck."

Bullock stars in the film as Loretta Sage, a reclusive romance-adventure author who's spent her career writing about exotic places. Channing Tatum is the novels' cover model, Alan, who strives to embody the books' hero character, Dash, in real life.

While the pair are promoting Loretta's latest book, she's kidnapped by eccentric billionaire Abigail Fairfax (Radcliffe), who wants to find the treasure featured in her newest novel. Alan sets out to rescue the author, as they're both thrown into an epic jungle adventure. Meanwhile, Pitt cameos as Jack Trainer, a CIA operative who swoops in to try and save both Loretta and Alan from the billionaire's clutches.

"Who knew Channing was going to prance like a little gazelle?" Bullock said of the massive explosion scene's perfect physical comedy elements. "We didn't know that Brad was going to flip the hair. I didn't know it was going to be so loud."

As it turns out, Pitt's luxurious lock-flipping may have been a brilliant stroke of comedic timing. According to Radcliffe, the film's many long, blonde wigs -- especially those work by Channing while playing a romance novel cover model -- had a way of impacting the actors' performances.

"Channing did turn into a different person in the wig," Radcliffe joked. "He would walk slightly differently and the spirit Fabio [possessed him]."

"He did make us all a little uncomfortable that day," Bullock added with a laugh.

The Lost City is due out March 25. Check out the video below to hear more about how Pitt's memorable cameo came to be.