Sci-fi disaster feature. After a series of sinkholes open in the ground, swallowing entire towns in their path, a group of school students find their bus precariously perched over the edge of one of them. As the teenagers teeter on the brink of death, it seems the only hope of saving them lies with paramedic Joan Conroy (Gina Holden) as she frantically tries to save her daughter from plunging to her doom.