Vi is failing at top spy school Rimmington Hall - even though the school motto is 'Failure is Not an Option'. To make it worse, nearly-stepbrother Russell Sprout is an A* student. Worst of all, Vi's shadowy nemesis Umbra is still at large. Can Vi unveil the arch-villain before she gets expelled and her parents ground her for ever? She'll need the help of old friends and new, including 9-year-old super-hacker Missy Fit and BFF Tamina, who aims to save the world in a different way ...