WATCH: The Gunman Trailer

Liam Neeson proved several years ago (and has tirelessly continued to prove since) that old guys can still kick cinematic ass. Now, Sean Penn is becoming part of that grand tradition with his new movie The Gunman.

Based on a novel by Jean-Patrick Manchette, the film presents Penn as a hired killer who wants out of his bloody profession to settle down. Things don't go down quite so smoothly and, you guessed it, he'll have to pick up the gun again.

Also starring Idris Elba, Ray Winstone and Javier Bardem, look for this one in theaters March 20.