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The Fidelius Charm and How to Use It

The question currently leading the voting in the jkrowling.com FAQ poll is this: What happens to a secret when the Secret Keeper dies? It’s a fascinating question in itself, but it also has wider implications and raises the issue of the Fidelius Charm in general. Is it as safe as it’s made out to be? What happens to the magic if the object it is cast on is destroyed, or if one of the people it is cast on is killed? And, of course, the main question itself: what happens when the Secret Keeper dies? Throughout the books there are a number of references to this particular piece of magic, and what with the events at the end of Half-Blood Prince (which I’m sure we don’t need to go through here), the issue of what happens when the Secret Keeper dies has come to far greater prominence.

The Fidelius Charm (from the Latin fidelis, meaning trusty or faithful) is “an immensely complex spell involving the magical concealment of a secret inside a single, living soul. The information is hidden inside the chosen person, or Secret-Keeper, and is henceforth impossible to find – unless, of course, the Secret-Keeper chooses to divulge it. As long as the Secret-Keeper refused to speak, You-Know-Who could search the village where Lily and James were staying for years and never find them, not even if he had his nose pressed against their sitting room window!” (PA10, emphasis added).

There are two instances of the Fidelius Charm being mentioned so far in the Harry Potter series. In the first instance (where the spell was cast to conceal the location of James and Lily), the Secret Keeper didn’t die: instead, the subjects of the spell (ie the people the secret was about) were killed instead. In this situation we could also ask the following questions:

Was the spell lifted when the protected person died or the protected object was destroyed?

Would the spell be lifted if the witch or wizard who owned the protected object died?

There has been no mention in the books of where James and Lily are buried. It seems a little odd that this hasn’t crossed Harry’s mind, and that he hasn’t expressed any interest at all in visiting their graves. Could it be that this lack of concern about his parents’ final resting place is down to the lingering effects of the Fidelius Charm? Could it be that the magic of the spell is guiding his mind away from any such thoughts? It must be possible, but even so it seems ludicrous to suggest that nobody could know the location of James and Lily’s graves unless Peter Pettigrew decided to tell them. Despite Harry’s odd lack of curiosity about where his parents are buried, the obvious conclusion must be that the magic of the Fidelius Charm ceases when the protected subject dies.

It is in the second instance of the casting of the spell that we can really ask, “What happens to a secret when the Secret Keeper dies?” and where the relevance to recent events really kicks in.

Here is a brief description of the two instances of the Fidelius Charm we have encountered so far:

In the first instance, assuming that the Fidelius Charm was cast on James, Lily, and Harry Potter, was the spell broken when some of the protected persons died? The answer, despite the circumstantial evidence of Harry’s lack of interest in their graves, must still be “Yes.” After all, once Voldemort had killed them, James and Lily Potter could be seen and were subsequently buried in a cemetery, and both Hagrid and Sirius saw baby Harry, who was subsequently left with Muggle relatives. It is worth noting that the implication of this is that if a group of people (or items) is protected, the death or destruction of any one of them is enough to break the spell.

Assuming that the Fidelius Charm was cast on the Potter’s home in Godric’s Hollow, was the spell broken when the protected object was destroyed? Again, the answer is “Yes.” Even Muggles were “swarming around” (SS1). Yes, Sirius said that he would rather have died than betray Lily and James (PA19), and Sirius never would have betrayed them. However, this doesn’t necessarily mean that the spell wouldn’t have been lifted if Sirius had been the Secret Keeper and had subsequently died. Sirius, as a Secret Keeper, was also planning to go into hiding (PA10). Would this just have been to protect himself, or to protect the secret that he ended up never carrying?

In the second instance listed above, Dumbledore was the Secret Keeper for the location of number 12, Grimmauld Place as the Headquarters for the Order of the Phoenix. Harry, although he was a wizard, could NOT see the house when he first went there. It was only when he read the note written by Dumbledore revealing the secret that the house appeared in front of him (OP4). So when Dumbledore died (and the Full Body-Bind Spell he put on Harry instantly disappeared) either:

1. The spell held even though the Secret Keeper died. No new member of the Order of the Phoenix will be able to enter number 12, Grimmauld Place. In fact, no witch or wizard who did not know the secret before Dumbledore’s death will be able to see number 12, Grimmauld Place (including Harry’s children, if he had any). This just doesn’t make sense. As time went on and the current members of the Order of the Phoenix died (by natural causes, we hope), the house would cease to exist in any world.

Or:

2. With Dumbledore’s death, the Fidelius Charm that guarded the house was lifted and number 12, Grimmauld Place could again be seen by a witch or wizard. After Sirius Black died, Dumbledore implied that the Fidelius Charm might not have held if Bellatrix owned the house, so they “had to move out until … we have clarified the position” (HBP1). However, since Harry, the new owner of the house, gave Dumbledore permission to use the house as Headquarters, the Fidelius Charm should have been in place until Dumbledore died.

Thus, whoever owns the item the spell is cast on needs to give permission for the Fidelius Charm to work. This makes complete sense, or there would be complete chaos in the Wizarding world. For example, Lucius Malfoy could put a Fidelius Charm on The Burrow to use as the Death Eaters’ headquarters, and the Weasley’s would never find their home again.

The Malfoys and Bellatrix Lestrange certainly knew where number 12, Grimmauld Place was, and they can probably now see the house. However, this doesn’t necessarily mean that they can easily enter the house. Harry is the legal owner; Sirius’s father put “every security measure known to wizard-kind on it” (OP6); and “most Wizarding dwellings are magically protected from unwanted Apparators” (HBP4) anyway.

With another Fidelius Charm (perhaps with Hermione performing the spell), the house could again be the Headquarters for the Order of the Phoenix. This must carry a certain amount of risk, however: if anybody who knew about the location of the house came by and found that no magic could make it visible to them, the conclusion about why it had disappeared must surely follow very easily. It’s a short step from deducing that the Fidelius Charm has been cast on the house to realizing why, and then the game will be up: Voldemort wouldn’t think twice about laying waste to the entire street, and just because number 12 can’t be seen, this doesn’t protect it from being destroyed if the whole street is obliterated.

This shows clearly that you have to be very careful about when and how you cast a Fidelius Charm, in order to make sure that the secret you intend to keep is indeed as secure as you wish it to be. It also highlights a fundamental weakness in the whole process: for all the complexity of the magic, beating the spell still comes down to one thing: kill the Secret Keeper, and you unleash the secret. James, Lily and Sirius knew this when they cast the spell to protect Harry all those years ago, which is why they attempted the ill-fated double-bluff that resulted in Peter Pettigrew taking on the Secret Keeping duties. Tragically for them, this attempted protection measure just played straight into Voldemort’s hands.

Addendum:

This question has now been answered by JK, but her official response actually raises more issues than it addresses. JK is, of course, the sole source of official information about the HP world and so what she says goes, it's as simple as that. What she says about the Fidelius Charm, however, imply that it is a seriously flawed piece of magic that none but the truly desperate would use.

For those who haven’t seen JK’s response, the official line is that the secret really does die with the Secret Keeper (or, more accurately, nobody else can be told the secret once the Secret Keeper is dead, so that it will be known only by those that the Keeper told when he was alive: when these people die, the secret will truly die with them).

The implications of this are far-reaching:

When the Potters were protected, what would have happened if Wormtail had chosen to die rather than betray them, as Sirius suggested he should? It would hardly have meant a much better deal for the Potters. In all likelihood, the only people in the whole world who knew their location (apart from Wormtail and Voldemort) were Sirius Black and Albus Dumbledore. If Wormtail had died without betraying them, then the Potters would have been sentenced to a life as shadow-people, unable to interact with anyone in the entire world except Sirius and Albus. Nobody else would have been able to see them, hear them, or speak to them. They would have had to steal food, clothing and anything else they needed. If they were injured, or became ill, they would be left to fend for themselves and possibly even die, as they would be unable to be seen by anybody at St Mungos even if they went there. And if and when Sirius and Albus died, they would be truly alone, forgotten by a world they couldn’t touch, until they themselves, unnoticed, passed away.

It wasn’t stated in JK’s response, but the implication is there that if a group of people are protected, then the deaths of some of them (but not all of them) would not break the charm. James and Lily both died in the attack – but what if Wormtail had died too, caught in the explosion that so nearly killed his master? Harry could then have been left helpless, a 1-year-old child unable to be seen, heard or touched by anyone in the world.

Of course this didn’t happen in the book: when Voldemort attacked the Potters, Muggles were swarming around in the aftermath and Harry could be seen by Hagrid, McGonagall and the Dursleys amongst others. The charm had indeed broken, which can only mean that it was cast by James or Lily in the first place. When the caster dies, the effects of the spell cease, and it this case it was only this that saved Harry from what could well have been a fate worse than death.

The situation with Grimmauld Place is equally convenient: not only was Dumbledore the Secret Keeper, he was also likely to be the spell caster. So, rather than Grimmauld Place disappearing into the ether, instead the spell broke and the house can be seen by the world again.

Therefore, on both of the occasions where the Fidelius Charm has been cast so far, it has been broken by the death of the caster. All things considered, if someone has to die this is by far the best way for it to happen. The death of the Secret Keeper can have catastrophic effects, and this makes the Fidelius Charm a fatally flawed piece of magic. And not only does the spell put the whole future of the people/objects that it is cast on at severe risk in this way, regardless of the Secret Keeper issue, it is still very easy to get around the charm. The last paragraph of the original article still holds, but you just have to replace the words “Secret Keeper” with “spell caster” and you have the truth…

This shows clearly that you have to be very careful about when and how you cast a Fidelius Charm, in order to make sure that the secret you intend to keep is indeed as secure as you wish it to be. It also highlights a fundamental weakness in the whole process: for all the complexity of the magic, beating the spell still comes down to one thing: kill the spell caster, and you unleash the secret.

And that’s how it is. The Fidelius Charm may sound like a fantastic piece of magic in theory, but in reality it is highly dangerous and provides far less protection than it promises. Without doubt it is best to avoid using it altogether.