In South-West England... a community is torn apart when a number of sinkholes open up and precious lives are lost. As the town mourn the loss of their loved ones from the earth's gaping wounds, they are unaware some have survived beneath the surface, after an underground lagoon cushioned their fall. Below ground... The survivors find themselves in a spectacular cavern with no way out. Desperate to get dry from the perishing cold, they must find a way to make a fire, to keep warm until they are rescued. Above ground... Fearing potential cave-ins the army is unable to form a rescue team. That's when the wheels are set in motion to fill in the holes, so that they can rebuild the town and carry on. Below ground... As their subterranean world is sealed from above, a story of friendship and fortitude begins, as the survivors struggle to find heat, light, food and essential medical supplies. Using their wits and their natural instincts for survival, they recycle the resources that fall through the sinkholes with them; a tree, a bed, a pharmacy and a blue Mondeo.