ollietheocto
On the day she knew she might die, Lily Evans Potter filed a Last Will and Testament with Gringotts. It named Severus Snape as her son's guardian.
The will was magically binding. Snape's consent was not required.
Voldemort fell on Halloween 1980. Harry Potter was three months old. He did not go to the Dursleys. He went to a man who had not slept in four days, who lived in a house that smelled like canal water, who sat in a cold chair at three in the morning because a baby would not sleep unless he was being held, and who had been a Death Eater, and who had been a spy, and who had lost the only person he'd ever loved, and whose first instinct when a three-month-old grabbed his finger in the dark was not to pull away.
This is the story of how Severus Snape became a father without deciding to.
Unlikely covers Harry's infancy through Year Two. It is a slow burn of the domestic kind: nappy changes and Potions labs and a castle that grows around two people who do not know they are building something until it is already built. It is also a story about institutional failure - what happens when a school is attacked from inside, when the adults see the danger and still cannot reach it in time, when doing everything right is not the same as winning.
By the end of Year Two, Harry Potter has spoken to a snake in public, fought a basilisk in a flooded chamber, faced a piece of Voldemort's preserved soul, and asked Fawkes for help without knowing that was what he was doing. Severus Snape has spent twelve months watching a child he raised from infancy walk toward danger and held very, very still.
Series tagline: Blood was never the magic that protected Harry. It was love.
Ships (slow burn, not the focus of this book): Draco/Harry (Drarry), Severus/Remus (Snupin)
Content notes: Canon-typical violence, child trauma (institutional, not abusive guardianship), possession/loss of autonomy, grief, medical content, animal harm. No sexual content. No character death beyond canon.