It’s one thing for someone with almost no prior acting experience to play Leonardo DiCaprio’s onscreen son in one of the most star-studded movies of 2021. It’s an entirely different thing to have improvised a line during a climactic scene that ended up in the final cut.

Robert Radochia, a junior and economics major at Connecticut College in New London, found himself in that position after receiving word last spring that he was cast as the son of Dr. Randall Mindy, played by DiCaprio, in “Don’t Look Up.” The black comedy is now nominated for four Academy Awards, including Best Picture.

The film, directed by Adam McKay (“The Big Short,” “Stepbrothers”) and available on Netflix since Christmas Eve, involves the discovery of a “planet-killing” comet by astronomers Kate Dibiasky (Jennifer Lawrence) and Dr. Mindy (DiCaprio). They calculate the comet will make a direct hit on Earth within six months. Meryl Streep stars as the U.S. President, with Jonah Hill as her son and chief of staff. Even the minor characters are played by household names, such as Cate Blanchett and Timothée Chalamet.

During pre-production, Radochia worked on building a narrative for his character. One of the ways did this was by analyzing the lines of his onscreen father. Dicaprio’s character is an intelligent if anxious protagonist who relies on medications to get him through the media circus that surrounds his predicting the end of the world.

“I didn’t get to read the whole script, but I used the lines I got as a guide for who my character was,” Radochia says.

He says his character’s first line of dialogue told him that Evan must take after his dad a bit. Dr. Mindy asks his son to rate how his new antidepressants are working on a scale of 1 to 10; Evan replies, “I’m a solid 4.

McKay had an unusual presence on set because of the pandemic.

“He was more of a voice in the sky. Because of COVID restrictions, they mostly just had him outside in a van where he had full view of every camera on set, and he would just make calls over the loudspeaker to give the actors directives,” Radochia says. 

McKay, who is known for encouraging actors to improvise lines on set, did that during the film’s climax, when Dr. Mindy’s family members and friends gather around the dinner table as they wait for a comet to hit Earth.

While the characters were eating and swapping stories, McKay’s voice boomed over the loudspeaker to address Radochia.

“Rob, let’s mix it up a bit. Try saying you fell asleep in the backyard and then something happened,” Radochia recalls the director saying.

Radochia remembers the nerve-wracking intensity of that moment and how he thought a string of expletives. Then he figured, “OK. What would Evan Mindy say?’”

Within 20 seconds, cameras were rolling.

“I just came out and said, ‘I’m thankful for that time I fell asleep in the backyard and woke up face to face with a baby deer.’ I kind of paused for a second, like I wasn’t sure if I was going to keep going, and then added, ‘That was the best day of my life,’” he says.

The line ended up making it into the final cut of the movie.

So how does a Connecticut College student wind up at an end-of-the-world dinner party with some of the biggest names in the film industry?

“It was very freaky,” Radochia says. “I’d done auditions in the past when I was around 10 years old, just some commercials and modeling and other stuff. But it was actually my mom who encouraged me; she forwarded me an email about local casting, so I just threw my audition tape out there. I was extremely lucky.” 

According to Radochia, the casting call for the film, which was shot in Boston in the spring of 2021, disclosed only that it was a Netflix production with DiCaprio starring. Little did he know he would be on the set of a $75 million production.

When asked about the experience of working with such a prestigious cast and crew, Radochia described the contrast between DiCaprio’s character and his real-life persona.

“In the movie, he plays someone who completely lacks confidence and has to cope with that by medicating, but that's not the presence he gives off at all in real life. Usually you'd see people getting into character on set, but Leo would just snap into it as soon as the camera rolled, and then go back to his normal self,” he says.

Radochia recalled one particularly funny moment when DiCaprio approached him out of the blue.

“I remember in between takes, I was sitting down on the couch, and he came up to me and he said, ‘I got to visit Koko the Gorilla before she passed.’ and I said, ‘Oh, nice,’ even though I had no idea who Koko the Gorilla was.”

KoKo the Gorilla was a female gorilla with an extensive vocabulary, who received worldwide attention when she covered a 1978 issue of National Geographic with her pet kitten, All Ball.

Radochia is now back at college, continuing to push himself into uncharted territory as an actor by taking an acting course with professor David Jaffe of the theater department.

“That's a whole different animal. I've never done theater in my life,” he says.

Caoimhe Markey is arts editor of The College Voice, Connecticut College's student-run newspaper.

To see 'Don't Look Up' on the big screen

What: "Don't Look Up"

Where: Garde Arts Center, 325 State St., New London

When: 7:30 p.m. March 24

Tickets: $12

Contact: www.gardearts.org, (860) 444-7373