Twelve-year-old Cassi Whelan and her dad have just moved into a repaired house on the edge of Christchurch's Red Zone. Although Cassi was only four when earthquakes decimated Christchurch, her memories still haunt her. An obsessive runner, she finds the wide-open spaces of the cleared Red Zone suit her perfectly. However, she becomes suspicious about strange comings and goings at the broken-down house next door. A chance meeting with a boy who lives on the other side of the house, who is a tech geek, leads to them setting up a surveillance system to investigate what's happening... and the adventure begins.