Jack Nicholson's Improv Scared Leonardo DiCaprio Senseless On The Set Of The Departed

The first time I saw "The Departed" was on a plane. Watching a movie thousands of feet up in the sky is not ideal, but the film was so immersive that it really didn't matter that I was hurtling through the air in a glorified tin can. I was hooked. Many of director Martin Scorsese's films are high-stakes experiences, but there is something about "The Departed" that sets it apart. The film tells the story of two moles, Colin Sullivan (Matt Damon) who is a plant in the police force for the Irish Mob, and Billy Costigan (Leonardo DiCaprio), who is a plant in the Irish Mob for the police force. When Sullivan and Costigan get wind of one another, what unfolds is one of the best cat and mouse dramas cinema has ever seen.

Anchored by a riveting Jack Nicholson in the role of terrifying crime boss Frank Costello, "The Departed" excels in its storytelling, walking the line of classic Scorsese gangster movie and high-stakes crime drama. It is the only one of Scorsese's films to ever win the Academy Award for Best Picture, but its win makes sense when you consider how good "The Departed" is. One of the things that adds to the film's impressiveness is just how much improv went into Nicholson's character of Frank, a boss who truly has no limits for what he will and will not do. In fact, Nicholson was so good at improvising that he even ended up giving co-star DiCaprio a good scare during one of the film's pivotal scenes. 

In an article for Variety, Nicholson details how he liked to improvise his part as Frank Costello. Scorsese was always very receptive to improvisation, a trait Nicholson confirms by saying, "Marty is very free with his ideas and very receptive to yours." In regards to his character as Frank, Nicholson explains that "we built this character layer by layer."

In one of the many intense conversations between Frank and Billy, Nicholson "wanted to come up with something different." He tells Variety:

"There's a scene in a bar where I'm scaring the s*** out of Leo's character with a gun. There wasn't any gun in the script ... I asked the prop master to hide a gun on the set, and to bring a fire extinguisher as well ... the look on [the prop master's] face when I asked for that fire extinguisher was priceless."

No fire extinguisher makes it into the actual scene, but Nicholson's decision to intimidate DiCaprio's character with a gun was absolutely the right one. DiCaprio appears genuinely surprised by the appearance of the weapon, and the scene is one of the best interrogations in the entire film.