A family fights for survival as a planet-killing comet races to Earth. John Garrity, his estranged wife Allison, and young son Nathan make a perilous journey to their only hope for sanctuary. Amid terrifying news accounts of cities around the world being leveled by the comet's fragments, the Garrity's experience the best and worst in humanity while they battle the increasing panic and lawlessness surrounding them. As the countdown to global apocalypse approaches zero, their incredible trek culminates in a desperate and last-minute flight to a possible safe haven.