Major Bill Cage, a military officer without combat experience, is abruptly reassigned and thrust into a fierce battle against alien invaders. Within moments, he meets his demise but takes down a formidable alpha alien in the process. To his shock, he wakes up at the start of the same day, trapped in a time loop that forces him to relive the battle repeatedly. Each death offers him a chance to grow stronger and master the fight, as he seeks a way to break free from this relentless cycle.