Beginning the summer before Harry Potter's 5th year. Snape has begun to infiltrate Voldemort's inner circle following the death of Cedric Diggory, but during a Muggle-hunting revel, an unknown woman uses magic to repel the Death Eaters. Acting on instinct, Snape rescues her, but is she really a Muggle? And how will her discovery change Snape's story, and Harry's himself?