The Marine 4: Moving Target follows the story of Marine John Stokes (played by Willa Holland), who finds himself on a mission to protect a rogue agent, Lucy Chen (played by Mika Hijii), from a group of deadly mercenaries. As Stokes navigates through the treacherous landscape, he must confront his own demons and face off against the ruthless leader of the mercenaries, Ray (played by John Pyper-Ferguson).