This gripping six-part mini-series follows the fate of a group of train crash survivors after the Earth is ravaged by a giant meteorite strike. Travelling from London to Sheffield when the meteor hits, a suspicious canister carried by scientist Harriet Ambrose (Nicola Walker - Spooks) ruptures, plunging the carriage-load of passengers into a state of suspended animation.

They awake to find a startling new and devastated world - with no sign of human life. What happened and how long were they asleep? Convinced that there will be other survivors holding the answers at a top-secret installation in Scotland known as 'Ark', Harriet persuades the group to embark upon a perilous journey across the UK. With threats ranging from acid rain to wild animals, their mission will be anything but easy - and with no guarantee that they'll find the answers they're so desperately looking for.

The star-studded cast includes Amita Dhiri (Milly from This Life, Christopher Fulford (Horblower, Cracker) and Treva Ettiene (Pirates of the Caribbean).