Shared family holidays at Creek House have been the backdrop to Millie’s summers since forever. Hanging out with the other kids – Matt, Charlie, Jem and her best friend Kat – has made it her favourite time of the year. But this holiday things are different – the childhood games that once filled their days have lost their appeal to everyone except Millie. It’s not until the final night that the others agree to a game of hide and seek. But in the time it takes Millie to count to twenty, Kat vanishes.