As Edge of Tomorrow begins, aliens have taken over most of Europe. Lieutenant Cage (Tom Cruise) is an American military spokesman forced into combat by a general (Brendan Gleeson) for reasons not made entirely clear. (Something to do with the general's fear that media manipulators such as Cage will make him the fall-guy if the human troop surge is unsuccessful.)
Cage has somehow achieved the rank of lieutenant without receiving any combat training or even learning how to turn the safety off on his weapon, so everyone in his group expects him to die quickly on history's second D-Day. When the battle arrives, he does manage to stay alive long enough to cross paths with super-soldier Rita Vrataski (Emily Blunt). She has been labeled the "Angel of Verdun," because she displayed nearly god-like skills in killing aliens at a previous battle.
As Cage is sprayed with alien blood, he appears to be dying. But then he suddenly wakes up—at the invasion's launching base on the morning of the attack. From there, he has to figure out why he is in a purgatorial time loop and how he can use his seemingly endless supply of lives to formulate the perfect plan to defeat the aliens.
Novelist Ursula K. Le Guin once suggested that in the best science fiction, the author should be allowed one reality-bending premise and then judged on how skillfully she can follow that premise's own internal logic. In Edge of Tomorrow, it is not the time-travel loop that is so hard to accept.
But it's harder to bear how the film fuses its sci-fi premise with an action movie's sensibility: one in which the characters become living, breathing video-game avatars, rather than human beings. And that doesn't work for this movie—because of the movie's own premise.
In the film's problematic second act, Rita tries to hide personal information from Cage because, as she reasons, the more you see another soldier as another human being, the harder it is to watch her (or him) die. The film tries to leverage this in the third act, but fails—largely because it never bothers to make either of these characters people or show their bond deepening. Instead, it loops through the battle scenes to show Cage's progress, suggestiing he is accumulating experience through montages in which Rita casually shoots her partner after each training session to "reset" the day.
In a very telling third act moment, Cage—weary from having lived the same day over and over—simply doesn't push a fellow soldier out of death's way. The screening audience howled with glee. Who cares, right? It's not as if, even in the movie's world, this grunt were a consequential person who was really, actually dead.
More than simply a joke that misfires, that scene is, I would argue, the film's most unintentionally honest moment and the one in which it becomes the very antithesis of the comedy classic it is so clearly invoking: Groundhog Day.