Lily Evans is looking forward to summer - until she finds the Marauders, England's top-selling band, hiding in her barn. Now, she has to deal with rockstar egos, an unwanted admirer, and the dark force that sent them into hiding in the first place.

Hermione grows up as a maths whiz instead of a bookworm and tests into Arithmancy in her first year. With the help of her friends and Professor Vector, she puts her superhuman spellcrafting skills to good use in the fight against Voldemort. Years 1-4. Sequel posted.