(It has been established fairly well by now on here that the Fidelius charm is not the most consistent and well-explained elements in the Potterverse. But we can still try to make sense of the madness…)

When reading the books, I had always rather taken it for granted that what Peter Pettigrew, as Secret Keeper to the Potters, kept concealed was the location of the Potter house in Godric’s Hollow.

However, as pointed out by various answers and comments to this old question by Slytherincess

  • the house was clearly visible to Hagrid when he came to collect Harry, as well as to the Muggle police/firefighters/paramedics that showed up soon after, to the wizards that later turned the Potter house into a memorial, and to Hermione when she and Harry turned up
  • Dumbledore must have known where the house was (and we must assume Peter wouldn’t be too eager to tell him of all people), since he was apparently able to set up various alarm spells to alert him if anything happened

In addition to this, merely concealing the location of the house itself would leave the people you’re trying to protect quite unprotected as soon as they leave to pick up groceries—as we see in Deathly Hallows when the Death Eaters outside Grimmauld Place catch glimpses of Harry, Ron, and Hermione if they Apparate a bit too far from the doorstep.


The alternative, which I am perhaps late in even thinking of, is that the secret was the Potters themselves, or at least their current location. There is some support for this:

  • In Prisoner of Azkaban, chapter 10, “The Marauder’s Map”, Flitwick describes the Potters’ Fidelius charm thus:

    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!

  • On J.K. Rowling’s old website, the answer to the question “What happens to a secret when the Secret-Keeper dies?” states:

    In other words, a secret (eg, the location of a family in hiding, like the Potters) is enchanted so that it is protected by a single Keeper (in our example, Peter Pettigrew, a.k.a. Wormtail). Thenceforth nobody else – not even the subjects of the secret themselves – can divulge the secret. Even if one of the Potters had been captured, force fed Veritaserum or placed under the Imperius Curse, they would not have been able to give away the whereabouts of the other two. The only people who ever knew their precise location were those whom Wormtail had told directly, but none of them would have been able to pass on the information.

Flitwick’s wording suggests (though perhaps not peremptorily so) that it would be possible for Voldemort to have his face pressed against the Potters’ sitting-room window at all, which would of course mean that at least the house itself was not concealed.

Rowling’s answer specifically talks about location and is more unequivocal, but that interpretation also brings up a whole slew of unanswered questions and logistical difficulties (or impossibilities).

For example, if the Potters went to the shops to buy groceries, would nobody be able to see them? And if Peter revealed the secret of their location to someone, would they become invisible and unplottable again as soon as they went somewhere else? And how could Peter even possibly reveal their location unless he was standing right next to them? If they went somewhere else, he would no longer know their location himself. And, as DVK points out in this answer, if this kind of Fideliusing were possible, why did Dumbledore not do the same with Harry later on when he knew that Voldemort was after him again?1


I cannot think of any other way the Potter Fidelius could have worked. Keeping the house concealed would be the logi(sti)cally sounder and less problematic option, but there’s quite a bit of circumstantial evidence in canon that indicates that this was not it. Keeping the Potters themselves hidden seems to have more canon support, but is a logi(sti)cal nightmare that engenders far too many impossibilities and unanswered questions.

So was Peter concealing the location of the Potter house, or the location of the Potters themselves… or something entirely different?

Is there any canon evidence or Rowling interviews that we have missed in the previous Fidelius-related questions that might answer this?


1 Or perhaps rather: if Peter simply revealed the secret to Voldemort, why was Hagrid and everybody else able to see Harry subsequently? He should still be Fideliused and thus invisible and unplottable, if that is indeed how Fideliusing a person works. If that were so, of course, there would have been no books—nobody would have been able to see or hear Harry, and he would have died from starvation among the rubble within a day or two.

  • 2
    I always understood the nose pressed against their sitting-room window to be a metaphorical remark/exaggeration.
    – ibid
    Commented Feb 21, 2016 at 4:04
  • @ibid As did I; but if it was in fact their location that was being hidden, it would make perfect sense as a literal, matter-of-fact statement. Commented Feb 21, 2016 at 4:06
  • 1
    @ibid Well, that’s rather the problem—we really don’t know very much about how the Fidelius charm does and doesn’t work. It’s so vaguely and inconsistently described that it’s nigh impossible to tell (to the point that it’s almost on its way to becoming an SFF meme in itself). This wouldn’t contradict any of the things we actually do know about it, though. Commented Feb 21, 2016 at 4:17
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    may be I didn't understand the question, but doesn't the Potters themselves being the secret imply they don't have to hide inside the house at all? They should be protected as the secret no matter where they are. Moreover, all other instances of Fidelius in the books show the charm protecting a house, I don't see why the case with the Potters should be any different.
    – user13267
    Commented Feb 21, 2016 at 11:00
  • 1
    @chirlu He was definitely wrong. Regardless of what the Fidelius charm was concealing, Harry was part of it. So even if it had still been intact and working spiffily, Harry would possibly be the only person left alive by then (apart from Peter) who should be able to see the house. Commented Feb 21, 2016 at 14:54

2 Answers 2


It did NOT protect the Potters themselves. Here is what Lilly wrote in a letter to Sirius (Harry Potter and the Deathly Hallows, Chapter 10):

We had a very quiet birthday tea, just us and old Bathilda who has always been sweet to us and who dotes on Harry. We were so sorry you couldn't come, but the Order's got to come first, and Harry's not old enough to know it's his birthday anyway! James is getting a bit frustrated shut up here, he tries not to show it but I can tell also Dumbledore's still got his Invisibility Cloak, so no chance of little excursions. If you could visit, it would cheer him up so much. Wormy was here last weekend. I thought he seemed down, but that was probably the news about the McKinnons; I cried all evening when I heard.

So they had to stay in the house to be protected. Leaving the house would endanger them and they did not dare to do it without the invisibility cloak.

This leaves really some open questions like - how could Hagrid and Bathilda see the house without knowing that Wormtail is the secret keeper.

One possible explanation comes from this quote:

'Here,' Moody muttered, thrusting a piece of parchment towards Harry's Disillusioned hand and holding his lit wand close to it, so as to illuminate the writing. 'Read quickly and memorise.'

Harry looked down at the piece of paper. The narrow handwriting was vaguely familiar. It said:

The Headquarters of the Order of the Phoenix may be found at number twelve, Grimmauld Place, London.

So it is possible that the secret keeper shares the location of the protected house by just writing it down. The Potters might have asked Peter to just write the location so that they can show it to whomever they want.

This again leave the question open how could Harry and Hermione see the house about 16 years later - Wormtail was still alive at that point. But it is possible that the Fidelius charm just fades away after some time.

  • Maybe the ones who casted the Fidelius charm were dead, that /might/ be the reason. Or instead, Harry itself was in on the charm and thus was able to see the location. Due to that he could've told Hermione and thus both were able to see it, even without realizing this caveat
    – Oak
    Commented Feb 21, 2016 at 12:01
  • Perfect! I had completely forgotten about that line in the letter. That settles it quite conclusively. Bathilda and Sirius had clearly been told the secret (since their visiting is actually mentioned in the letter), it's just everyone else seeing the place that's problematic. @Oak The caster dying doesn't seem to break the charm, though; at least, the two likeliest people to have cast the charm on Grimmauld Place would be Sirius and Dumbledore, and the charm stays in place after they're both dead. Commented Feb 21, 2016 at 12:26
  • Yes, but no one revealed Grimmauld's place unlike Godric's Hollow. Actually, it was revealed later on in the storyline (by Hermione Apparating with Death Eaters by accident)
    – Oak
    Commented Feb 21, 2016 at 14:13
  • @Oak I don’t understand what you mean there. “No one revealed Gimmauld’s Place unlike Godric’s Hollow”? Harry was definitely ‘in’ on the Potter Fidelius and should always be able to see the house (which is why I only mentioned Hermione in the question, not Harry), but Hermione shouldn’t. It’s clear from the book that Harry doesn’t tell Hermione where it is: he sees it, speeds up, says, “Look”, and then Hermione sees it; but since the Secret Keeper (Peter) is still alive, he shouldn’t be able to tell Hermione anyway, even if he wanted to. Commented Feb 21, 2016 at 15:02
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    @Lucharx But Harry couldn't have revealed the secret, since Peter was the Secret Keeper and he was still alive at that point. Also, apparently more people is able to see the house (because they left signs in it). The Fidelius Charm had to broke at some point, but I don't know when or how.
    – IloneSP
    Commented Apr 16, 2021 at 2:16

My take is that Wormtail was, at the very least, concealing the fact that the Potters lived in whatever house was their home, and may further have concealed the fact that the Potters lived in Godric's Hollow.

The breadth of the Fidelius Charm's power was stated as preventing even direct observation of the protected secret from causing the secret to be known. Quite apparently, except for a deliberate communication made by the Secret Keeper (whether written or verbal), it is impossible to learn the protected secret by any means whatsoever, whether it be direct observation (ie., looking directly through the Potters' sitting-room window) or as an inference drawn from any fact or assemblage of facts. Quite simply, the spell interferes with everyone's capacity to reason, with regard to the protected fact. The implications of this are:

  • If Voldemort had sent an owl to the Potters, and then tracked the bird, the spell would either cause Voldemort to forget to tail the bird, or cause him to lose track of it during its flight, or to make him conclude that the owl had gone to the wrong house.
  • If Voldemort had ordered one of his supporters to order a house elf to visit the Potters, and then return and report on where he had been, the spell would cause Voldemort to disbelieve the elf's report, or to be distracted by other matters just as he was thinking of asking the elf to say where he had been.
  • Voldemort could read the lease or mortgage paperwork for the Potter's house, and the spell would make him think that the Potters may have leased or bought the place, but lived somewhere else.
  • He could burn down every house in the world, except theirs, search the remains of each house and not find them, and upon arriving at the only house on Earth still standing, the spell would make him dismiss the house from consideration as being their residence.
  • He could read the Wizarding equivalent of the phone book, find their listing in it, read that they lived at such-and-such a place in Godric's Hollow, and the spell would make him concluded that it was an outdated listing.

And so on. The narrative of the story makes it very clear that betrayal by Wormtail was the only way for Voldemort to learn where the Potters lived. That means that the Fidelius Charm has a vast and narrowly-focused power.

  • 1
    Not to mention Harry couldn't physically see 12 Grimauld place when he did not know the secret. Applying the secret to a person could produce unintended and negative side effects, such as James or Lilly bleeding profusely but unable to seek medical attention. Perhaps the charm could not be cast on a person, as it would be a literary magic bullet.
    – jfa
    Commented Jul 14, 2017 at 15:25

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