Secret-Keeper

A Secret-Keeper is a single, living witch or wizard designated to be the sole keeper of a specific secret through the use of the Fidelius Charm. The secret information, such as the location of a person or place, is magically extracted from reality and implanted into the very soul of the Secret-Keeper. Consequently, the information becomes undiscoverable by any means—magical or mundane—unless the Secret-Keeper chooses to divulge it voluntarily. The role is one of absolute trust and immense responsibility, as the safety of the hidden person, family, or organization rests entirely on the Secret-Keeper's loyalty and ability to protect the secret.

The creation of a Secret-Keeper is the primary effect of the Fidelius Charm. As explained by Professor Flitwick, the charm involves “hiding a secret inside a single, living person.” Once the charm is successfully cast, the chosen Secret-Keeper becomes the magical focal point of the information.

• Imparting the Secret: The information is no longer inherently knowable. For example, a hidden house becomes unplottable, invisible, and undetectable to anyone who has not been told of its existence by the Secret-Keeper.
• Divulging the Secret: The Secret-Keeper is the only individual who can share the secret. This can be done verbally or in writing. Those who are told the secret are magically bound not to pass it on to others. For instance, Albus Dumbledore had to provide Harry Potter with a piece of parchment containing the address of 12 Grimmauld Place before Harry could see the building.

The magic binding a Secret-Keeper is powerful and comes with specific rules and consequences that are critical to its function.

• Voluntary Disclosure: A Secret-Keeper cannot be forced, tortured, or magically coerced (e.g., via the Imperius Curse or Veritaserum) into revealing the secret. The disclosure must be a willful and voluntary act.
• The Secret-Keeper's Death: If a Secret-Keeper dies, a crucial change occurs. Anyone to whom the Secret-Keeper had previously confided the secret becomes a Secret-Keeper themselves. This was demonstrated after the death of Albus Dumbledore; every member of the Order of the Phoenix who knew the location of 12 Grimmauld Place became a Secret-Keeper and could, in turn, pass the secret on to others. This diffusion of the secret makes it significantly less secure.
• Target of Attack: The Secret-Keeper, rather than the hidden secret itself, becomes the primary target for enemies. As long as the Secret-Keeper remains silent, the secret is safe. This is why Lord Voldemort hunted Peter Pettigrew to learn the Potters' location, rather than searching Godric's Hollow directly.
• Inhabitants of the Secret: Individuals who are part of the secret from the beginning (e.g., those living in the house when the Fidelius Charm is cast) are aware of their own location but are magically prevented from passing the information on. Only the designated Secret-Keeper can do so.

• Peter Pettigrew: He was the Secret-Keeper for the hiding place of James and Lily Potter in Godric's Hollow. He betrayed them to Lord Voldemort, leading to their deaths. Sirius Black was originally meant to be the Secret-Keeper but convinced the Potters to switch to Pettigrew at the last moment.
• Albus Dumbledore: He was the Secret-Keeper for 12 Grimmauld Place, the headquarters for the Order of the Phoenix. His death resulted in over two dozen people becoming Secret-Keepers in his place, which ultimately compromised the location's security.
• Arthur Weasley: He was considered to be the Secret-Keeper for The Burrow when its protective enchantments were reinforced during the Second Wizarding War. However, the plan was abandoned as it would have made him a primary target for Death Eaters.
• Bill Weasley: He served as the Secret-Keeper for Shell Cottage, the home he shared with Fleur Delacour. The cottage became a vital safe house for Harry Potter, Ron Weasley, Hermione Granger, and others after their escape from Malfoy Manor.

The concept of the Secret-Keeper is a pivotal plot device throughout the *Harry Potter* series, acting as the catalyst for the entire story and a recurring element of security and betrayal. The betrayal of the Potters by their Secret-Keeper, Peter Pettigrew, is the foundational event of the series. It directly caused the deaths of James and Lily, made Harry an orphan, led to Lord Voldemort's first downfall, and resulted in the wrongful imprisonment of Sirius Black in Azkaban. The reveal of this truth in Harry Potter and the Prisoner of Azkaban fundamentally reshapes Harry's understanding of his past. During the Second Wizarding War, the Fidelius Charm and its Secret-Keepers are crucial for the Order of the Phoenix's strategy. Dumbledore's role as Secret-Keeper for the headquarters ensures its integrity, while his death and the subsequent complication of the charm's succession highlight the war's mounting stakes. Later, Bill Weasley's role as Secret-Keeper provides the heroes with a desperately needed sanctuary at a critical moment.

• In the film adaptation of Harry Potter and the Order of the Phoenix, the note revealing the location of 12 Grimmauld Place is shown to be written by Alastor 'Mad-Eye' Moody. However, in the novel, it is confirmed that only Dumbledore, as the Secret-Keeper, could have written the note.
• The Pottermore website describes the Fidelius Charm as “fiendishly difficult” to cast, which explains why it is not used more widely to protect everyone at risk. (Pottermore)