On the eve of his departure for Japan, Rob (Michael Stahl-David) sees his going-away party as an opportunity to confess unresolved feelings and tie up loose ends. His agenda takes an unexpected turn when a jolt shakes the revelers. The crowd quiets down to watch news reports of an earthquake, then rushes to the roof to assess the damage. A fireball explodes on the distant horizon. A power failure follows. Confusion gives way to panic as the partygoers stumble through the blackout and into the streets. Amid the human screams and one inhuman roar, Rob and his friends must traverse a landscape that has changed, overtaken by something otherworldly, terrifying, monstrous.