While Paramount Pictures is due to release the action-thriller Gemini Man in theaters this weekend, some may or may not know that this is a project that’s been in development in Hollywood for decades, and our look at an alternate version of the movie has surfaced online. The concept for Gemini Man—an aging government assassin is hunted by a younger clone of himself—originated with Darren Lemke in 1997 and was sold to Walt Disney Pictures. The first director attached was Tony Scott, and while actors like Harrison Ford, Tom Cruise, and Brad Pitt circled the film, the project was considered unfilmable because technology had not yet advanced to the point that the same actor could play both the older and younger versions of the lead character.

That didn’t stop the studio from trying, and indeed at one point The Grey and Smokin’ Aces filmmaker Joe Carnahan threw his hat into the ring with his top casting choice: Clint Eastwood. With Gemini Man finally hitting theaters with Will Smith in the lead role and Ang Lee in the director’s chair, Carnahan has re-shared the sizzle reel he put together to pitch Disney and producer Jerry Bruckheimer on his vision for the project. In keeping with Carnahan’s style, it very much feels like a gritty character-driven thriller, and he used footage from Eastwood’s films to have the actor play opposite himself for the purposes of this pitch.

It’s a fun look at what could have been (it's quite a different approach than Lee's) and also a peek behind the curtain at how directors land big projects. Indeed, sizzle reels like this are used frequently by directors to show a studio or producers a visual representation of the kind of movie they want to make.

Carnahan’s version of Gemini Man never got past some CG tests with actor Jon Voight, but you can take a stroll down “What If?” lane in the video below.