The story starts with Major William Cage who is a public relations officer in the military was forced to join the front line of the battle against the aliens. He refused since he has no experience against fighting or whatsoever but his superior arrested him and drag him to the camp with the note of him being a deserter or a liar who is proclaiming himself as a major. Of course, the day came when he is sent on the field and finds himself lost since he has no experience and was killed by an Alpha which sent him on a infinite loop.
Whenever he dies the day restarted again and again until Rita told him his mysterious condition and ask him to help her fight against the aliens. His task is to find the Omega and at the same time to train himself to fight the aliens. The story goes on and on with him dying and the day repeating though it was a bit funny since whenever Rita died or they made a mistake he is forced to kill himself or accidentally kill himself while groaning. Though at some point I pity William since he is forced to battle even if he is a civilian and he fought like a thousand battles while watching Rita dies again and again. But what saddens me the most is when they all die in the end but at the same time I feel happy since they are all again alive with Cage being a major again.