Harry Potter - Secrets of Hogwarts

When cast upon a single dwelling that fits within range, it becomes a secret, infallibly invisible and inaccessible by anyone else. This effect reaches to the dwelling's property lines, or if no property lines are defined, the edge of the hemisphere centered on the caster at the time of casting. You choose yourself or one person within the area of the spell to be the Secret-Keeper. If the Secret-Keeper tells someone the secret (the location of the dwelling) verbally or in writing, that person can see the secret like the Secret-Keeper and step onto the property. It's impossible for anyone other than the Secret-Keeper to share the secret. If the Secret-Keeper dies, everyone who knows the secret becomes Secret-Keepers and can share the secret with others. Three dimensional space is warped around the secret, as if the space occupied by the secret never existed. If a person walks directly towards the secret, they will magically appear on the other side.