Secret-Keeper

Your hero has a dirty little secret that is central to the character and the show's main plot. They might be a superhero, or he might have a lab in his bedroom, or she might be a witch. There will sometimes be one regular Joe who knows about the hero's secret, and will also keep it secret. The Secret Keeper can be family, though it's very uncommon for them to be parents. It may require a Secret Relationship, if public knowledge of the relationship is a danger to the secret. Often, the existence of a Secret Keeper is only hinted at, rather than explicitly revealed to either the hero or the audience. The phrase originated in Harry Potter, where the Fidelius Charm hides a secret within a living person's soul (that person would then become the "Secret Keeper"); everyone else in the world other than the chosen person would be unable to learn the secret unless directly told of it by the Secret Keeper. Even if they originally knew the secret, the details would become muddy in their minds unless reminded by the Keeper. See also Tongue-Tied, for when a character is forced to keep a secret. See also The Confidant, someone who keeps non-heroic secrets. For cases in which the hero doesn't know that someone knows their secret, see Secret Secret-Keeper. Frequently discovers Keeping Secrets Sucks, and is witness to The Masquerade Will Kill Your Dating Life.