Harriet Potter gets transported into the past and end up in 1976. She meets the Marauders, her mother, and most of all, young Severus Snape.

Harry, as the Girl-Who-Lived, struggles to cope with her not so wonderful life, had to learn Occlumency to protect her mind from Voldemort, but in doing so, she found her Underworld King in the most unlikely person. Snarry - teacher/student relationship. Underage.

Harry underwent a drastic change on his 15th birthday, then few months later, he suffered potion accident that changed his life around a hundred and eighty degree. Severitus/gender-bender/DracoHarry not slash.