Obsessed with @sideprince's theory (can’t reblog, unfortunately, so I’m just going to link) about what Snape was searching for at Grimmauld Place when he last visits it in Deathly Hallows: a method of communicating with Harry. I think it’s entirely plausible that Snape, who knew about the marauders map and the invisibility cloak, would have deduced that an object that like the mirror could exist.
It also hangs well together with Snape’s focus on communicating with Harry in Deathly Hallows; in each interaction Harry has with Snape in Deathly Hallows, Snape is desperately trying to connect with him. The Patronus, his attempts to find him in the castle, his dying breaths—even indirectly, in his use of Phineas Nigellus Black.
I also like this theory because it fits well with one of my own: that Snape’s search of Grimmauld Place was in itself a message.
There's no denying that Snape’s last visit to Grimmauld Place was emotional—we see it in his tears over the letter—and even before that, he was likely rattled. His visit forced him to relive his killing of Dumbledore and underscored how irrevocably he was cut off from anyone who had known his true self. Snape is likely grieving and reconciling with his changed mission and the path ahead, as Harry must do during The Forest Again. (One of these days I’ll sit down for long enough to write how the photo of Lily:Snape :: resurrection stone:Harry… unless someone else has already written it in which case drop the link please!)
Given his emotional state, it’s easy to explain the mess he makes while searching. But why did he leave it that way?
Snape does lash out emotionally. But in most cases, given time and/or a reminder of his mission, he is able to master those emotions and pull himself back to the task at hand. So unless he was rushed, or deemed the house of Black to be below the basic effort of setting it to rights (both very real possibilities, for sure) it is somewhat uncharacteristic of him to leave the house in its ransacked state. Which to me begs the question: could it have been an intentional choice?
Perhaps, in the absence of finding something more concrete with which to reach Harry, he uses the search itself to send him a message:
Beware! The security of the house has weakened; stay on your toes and don’t get complacent. A lesson in defense to anyone who might be inclined to return to the house (how very Snape!) After all, Snape doesn't know that Mr. Weasley has said as much to Harry before he even arrives:
"Well, Mad-Eye set up a couple of curses against Snape in case he turns up there again. We hope they'll be strong enough both to keep him out and bind his tongue if he tries to talk about the place, but we can't be sure. It would have been insane to keep using the place as headquarters not what its protection has become so shaky."
But with evidence that there has been an intruder, the trio could reach the same conclusion. And they're right to be careful; within days Death Eaters are surveilling the house.
But there’s also another layer one could read into this: You're being protected. The intruder, while callous and disrespectful of the house and its owner, has not broken the Fidelius Charm.
Hermione and Ron get very close to reaching this exact line of reasoning:
“Death Eaters, for sure,” said Ron, as he, Harry, and Hermione watched from the drawing room windows. “Reckon they know we’re in here?” “I don’t think so,” said Hermione, though she looked frightened, “or they’d have sent Snape in after us, wouldn’t they?” “D’you reckon he’s been in here and had his tongue tied by Moody’s curse?” asked Ron. “Yes,” said Hermione, “otherwise he’d have been able to tell that lot how to get in, wouldn’t he? But they’re probably watching to see whether we turn up. They know that Harry owns the house, after all.”
They don't quite get there because Hermione assumes the only reason the Fidelius has not broken is the tongue-tying curse. Sure, after killing Dumbledore and cursing George, they're not about to give Snape the benefit of the doubt.
But it also seems to be the case that tongue-tying only affects verbal communication; there's no indication that it would stop one from sharing the protected information in other ways. And after all, the location of Grimmauld Place can be shared non-verbally—Dumbledore revealed the location of Grimmauld Place to Harry in writing, and we find out in just a few chapters that the location can be shared via side-along Apparition. So an intelligent wizard bent on sharing the location could very well get around the tongue-tying curse; indeed, the Order aren't discounting this possibility.
Yet Grimmauld Place remains secure until the trio accidentally let a Death Eater in themselves. Perhaps Snape was planting a seed; if the trio were just a little less convinced that the curses on Grimmauld Place were binding Snape, they might consider whether there was another reason Snape wasn't sharing the location with the Death Eaters. A seed, perhaps, that could germinate into doubts about Snape's allegiance and set the stage for future communication…?
I admit there’s nothing really in the text to support this little pet theory of mine, I’m mainly just musing here. But it’s a fun idea to roll around, so thought I’d share :)
There's an aspect to this theory that feels connected to the kind of subtlety Dumbledore used to convey the relevance of the Hallows to Harry? Harry has to really think about it and put the pieces together but if he does he could realize that Snape is trying to reach him. I completely agree that he left a trail in Grimmauld Place to make sure the Order knew he was there. Had the trio kept track of Snape more, even for strategic reasons, rather than just hated him, then after they exposed Grimmauld Place to Yaxley accidentally they would have wondered why Snape hadn't done the same. Of course, even then they would have assumed he hadn't thought to. But like with the realization about the Hallows, after months of odd questions with no clear answers, the questions themselves would have pointed towards an answer together, if that makes sense. Harry figures out the Hallows because of questions like, why did Dumbledore leave him an old snitch? Why did he leave Hermione a book of fairy tales? what's this weird symbol that shows up on a grave and Mr. Lovegood? Without all these questions left hanging in the air, Harry wouldn't have sought answers. The lack of clarity was what fueled his curiosity; it could have been the same with Snape, had Harry considered him worth thinking about.
Why didn't Snape reveal Grimmauld Place to any Death Eaters via side-along apparition? Why did he search Headquarters when he knew it was abandoned? He must have known it was empty or else he wouldn't have gone there. Snape was connected to the sword of Gryffindor by a goblin and Bellatrix Lestrange, but the trio keep assuming someone else put the real sword in the pool in that forest and don't even consider Snape. It also doesn't occur to any of them that Snape has to work in an office where Dumbledore's portrait is hanging. All the times they talk to Phineas Nigellus' portrait they aren't curious about Snape because they've dismissed him and have no interest in him other than hating him.
This is how Snape succeeds as a spy, however. The same treatment that caused him years of suffering and bullying at school becomes his greatest asset. He gives people little reason to like him, and then hides being their biases. His obvious cleverness, talent, and ability to be calculating are overlooked by people who let their dislike dictate their feelings and cloud their rationality.
