ET got a front row seat to Bradley Cooper's bromance with Limitless star Jake McDorman when we dropped by the set as they shot the sixth episode, featuring Cooper.
"I learn so much from Bradley all the time," McDorman admitted. "He's so involved in the process in front of the camera and behind the camera that I just really have learned a hell of a lot from being around him."
"He's crushing it," Cooper gushed.
WATCH: Bradley Cooper Meets His Successor in Mind-Bending CBS Thriller 'Limitless'
McDorman plays Cooper's successor on the mind-bending CBS thriller, based on the 2011 big-screen hit. In the TV adaptation, struggling twentysomething Brian Finch (McDorman) is introduced to the mysterious drug, NZT, by an old acquaintance. His life is forever changed when the drug makes him "the smartest person in the world."
"You're on the verge of having a life that most people can't even begin to imagine," Cooper tells McDorman in a clip.
McDorman said one of the things that drew him to the project was the origin story of how NZT was created and Cooper dished on how writers came up with the name of their fictional miracle drug for the movie.
WATCH: Why Bradley Cooper Is Hollywood's Coolest Leading Man
"We were batting around like 30 different combinations of three letters and NZT just sounded right," Cooper said. "You realize that people are going to say it many times in the movie, so what's a combination of letters that isn't so annoying?"
Watch Cooper on Limitless Tuesday night at 10 ET/PT on CBS.