As cities crumble under the weight of a devastating airborne virus, the Miller family finds themselves trapped in an underground fortress with a team of experts racing against time. With chaos on the surface and hope dwindling, Jack, Mary, and their son Billy must confront not only the relentless threat of infection but the moral dilemmas of survival.

As desperate measures blur the lines between right and wrong, they'll discover that the most significant battles are fought within, where nightmares materialize and trust is put to the ultimate test. In a world spiraling into darkness, can they unearth a cure before it's too late, or will they become just another victim of the pestilence?