Severitus

An alternative universe story in which Harry Potter is actually (secretly) the son of Severus Snape and Lily Evans, rather than James Potter and Lily Evans. See Different Parentage.

Lilys Charm

• (1) Lily's Charm (Harry Potter) by Obsidian Embrace
  In a story spanning two decades, Lily and Severus attempt to control the powers of the Dark Mark after Lily's life is threatened. Seventeen years later, Harry uncovers a long-buried truth about his parents.