Olly Brown never gets to take home the Year 6 class hamster because his overprotective dad has some weird hang-up about how much responsibility pets are and how sad it is if/when hamsters die. But then the most amazing thing happens: a hamster shows up in Olly's house anyway - and it can communicate with him! This new hamster, Tibbles, is in awe of Olly, and it turns out, Tibbles is not alone: there's a whole civilisation of super-advanced, intelligent hamsters who seem to be worshipping Olly ... as a god? This is so awesome! But how is this possible??? Spoiler alert: Could it be that when his geeky dad was eleven years old, the test capsule he shot into space had some unintended hamster passengers - with mindboggling unintended consequences?