‘Indiana Jones’ star Karen Allen explains how she got comfortable with ‘thousands’ of snakes on set

Warning: This article contains spoilers for "Indiana Jones and the Dial of Destiny."

More than 40 years after "Raiders of the Lost Ark" became a blockbuster in 1981, the iconic series returns to the big screen for one last installment, "Indiana Jones and the Dial of Destiny."

But is it really the end of the beloved franchise?

"It's never over until it's over," Karen Allen, who plays the titular character’s primary love interest, Marion Ravenwood, tells TODAY.com. “(But) I think we can assume. They’re certainly saying this is the last one.”

Allen's original role catapulted her to stardom back in the '80s, and in the latest "Indiana Jones" film, which premiered in theaters June 30, Allen surprised audiences with a cameo appearance as Marion. She says it hurts her heart to think that the series is over.

More than that, however, the actor says she wishes Ravenwood would have played a "more vigorous role" in the final film, which stars Ford, Phoebe Waller-Bridge and Antonio Banderas.

"I imagined somehow that she would be more actively involved in the last film," Allen says.

Despite being disappointed, Allen says she's happy that Marion gets closure in "The Dial of Destiny."

"I'm glad she has a little moment at the end of the film that at least brings her back into the story," Allen says.

Allen initially made a name for herself in the 1978 film, “National Lampoon’s Animal House,” and was considered for the role of Princess Leia in the original “Star Wars“ (which ultimately went to Carrie Fisher), before nabbing her breakout role in Steven Spielberg’s “Raiders of the Lost Ark.”

In a phone interview with TODAY.com, Allen walked us down memory lane, sharing some behind-the-scenes details about how they pulled off the action-packed scenes that made "Raiders of the Lost Ark" a classic.

Surrounded by snakes

One of the most famous scenes in the 1981 film is when Allen and her co-star, Harrison Ford, become trapped in the Well of Souls, a secret vault hidden beneath an Egyptian temple full of writhing snakes — which was filmed with live animals, Allen says.

"They brought in thousands of what's called a 'glass snake,' which is not a true snake, it's a reptile, and they were between three and four feet long," Allen explains.

Along with the non-threatening reptiles, real snakes were also brought, Allen says.

"There were pythons, who were serious biters and very dangerous, and we had to be very careful and there were a few people who were bitten by them. And then we also had cobras that had to be treated with extreme care and they were kept in a very, very special way. And we had ambulances on the set with detox," the actor explains.

Despite giving most people the creeps, Allen says she wasn't afraid of the reptiles — at least not the glass snakes, anyway.

"Those, literally, you could pick up and put on your lap," she says. "I remember sticking my finger in their mouths just to prove to myself that they were as harmless as I was being told they were. And they were, indeed, fairly harmless."

Along with being harmless, Allen says the snakes were also "camera shy" and didn't like the hot glare of the lights used on the set of the film.

"They would get us on the set, then they'd bring hundreds and hundreds of snakes out and put them all around us and they would immediately start to want to leave and go someplace else."

Allen says Ford had it somewhat easier given the actor wore long pants and boots in nearly all the scenes.

“I was there barefoot and my legs completely exposed,” Allen says, laughing. “So, it was a little bit different sort of relationship to the snakes.”

Feeling flammable

Perhaps more daunting than the snakes was the now-iconic white dress Allen wore in the original movie.

According to Allen there were 12 iterations of the dress made for "Raiders of the Lost Ark" and shipped to one of the movie sets in England.

"It was only then that they discovered that because of the fabric they were made with, it was going to be impossible to fireproof them," Allen explains.

Famously, down in the Well of Souls, Indy and Marion were surrounded by fire, from torches lining the wall to flames burning on the ground.

To make it work with the pre-made dresses, the set crew had fire safety equipment ready to go.

"On both sides of the camera, on either side, people were literally standing there with fire extinguishers and wet blankets and stuff to throw on me if my dress went up like a flaming white cascade," Allen says.

Working with leading men of the '80s

When it came to acting opposite of Ford, one of Hollywood's most illustrious leading men, Allen "had a blast working with Harrison," she says of the three movies they made together.

In 1984, Allen worked with Jeff Bridges in the sci-fi romance "Starman," during which she had "a wonderful time," she says.

She also starred in the 1988 Christmas film "Scrooged" with Bill Murray, an experience she says "challenged" her.

"Bill Murray challenged the hell out of me in 'Scrooged,' she says. "Just because he never wanted to say any of the lines that were written down for him. So it was a constant sort of, 'OK, what are we doing today?'"

This article was originally published on TODAY.com