Zardiphillian B.

AU fic. Since his early childhood, a mysterious man has been watching over Harry, helping him in ways that no one else can. It's too bad that this guardian happens to be Harry's most hated teacher, Severus Snape. But what happens when Harry finds out the truth, and, in the wake of new threats from Voldemort, feels he can no longer trust Snape? This starts out when Harry is three years old, and then jumps to his fifth year. It is mainly a story of Sev and Harry's (non-slash) relationship, but does have an actual fifth year plot in later chapters.