The Short Version
Spoilers ahead, of course, though I suspect most of you know at least the movie version.
Here’s the short answer. The person trying to steal the Sorcerer’s Stone isn’t Snape. It’s Professor Quirrell, who is carrying Voldemort on the back of his head. Harry gets the Stone through a clever enchantment on the Mirror of Erised, and Quirrell can’t touch him because of the protection his mother left when she died for him. Let’s walk through it.
Where We Left Off
All year, Harry, Ron and Hermione have been tracking a mystery. Something is hidden under a trapdoor guarded by a three-headed dog named Fluffy. They work out that it’s the Sorcerer’s Stone, made by the alchemist Nicolas Flamel, which can turn metal into gold and make the Elixir of Life.
They’re sure Snape is trying to steal it. He limps after an encounter with Fluffy, he seems to jinx Harry’s broom at Quidditch, and he’s overheard pressuring Quirrell in the forest. Meanwhile, Harry sees a hooded figure drinking unicorn blood, and a centaur warns him that Voldemort is coming back.
The Clue From Hagrid
After exams, Harry realizes something odd. Hagrid always wanted a dragon, and a stranger in a hooded cloak just happened to win him a dragon egg in a card game at the Hog’s Head pub.
Hagrid admits he told the stranger how to calm Fluffy: play him a bit of music and he falls asleep. Harry runs to tell Dumbledore, but Dumbledore has just been called away to London by an urgent owl from the Ministry. That’s the moment the three decide to go after the Stone themselves.
Through The Trapdoor
The obstacles are a tour of the Hogwarts staff. Fluffy falls asleep to a flute Hagrid carved for Harry. Devil’s Snare grabs them until Hermione remembers it hates light and fire. Then there’s a room of flying keys, and Harry, the youngest Seeker in a century, catches the right one.
Next comes a giant chess game. Ron directs it and sacrifices himself so Harry can win. A mountain troll is already knocked out. And finally, there’s Snape’s puzzle: seven bottles, a riddle, and fire on both sides. Hermione solves it with pure logic and says one of the best lines in the book, that she’s just books and cleverness, and that there are more important things, like friendship and bravery.
The Reveal
Harry goes on alone. In the last chamber, he finds the Mirror of Erised, and in front of it, not Snape, but Quirrell, the stuttering Defense Against the Dark Arts teacher.
Quirrell explains everything, without a stutter. He let the troll in on Halloween. He jinxed Harry’s broom. Snape was muttering a countercurse to save Harry, and even asked to referee the next match to protect him. Snape had been suspicious of Quirrell all along.
The Man With Two Faces
Then Quirrell unwraps his turban. On the back of his head is a second face: Voldemort. Since his defeat, Voldemort has been a kind of shadow, unable to live on his own. He shares Quirrell’s body, and the unicorn blood in the forest was to keep him going until he could make the Elixir of Life.
It’s one of the creepiest images in the series, and it explains why Harry’s scar burned every time he looked at Quirrell from behind, during the welcome feast and afterwards.
How Harry Gets The Stone
Quirrell can’t work out how to get the Stone out of the mirror. So he makes Harry look. Harry sees his reflection smile, put a red stone into its pocket, and then he feels the real Stone drop into his own pocket.
Later, Dumbledore explains the trick. Only someone who wanted to find the Stone, find it but not use it, could get it from the mirror. Anyone who wanted to make gold or live forever would only see themselves using it. Harry just wanted to stop Voldemort.
Lily’s Protection
When Quirrell grabs Harry, his hands blister and burn. He can’t touch Harry’s skin. Harry passes out, and wakes up three days later in the hospital wing.
Dumbledore tells him why. Harry’s mother died to save him, and that kind of love leaves a mark. Not a scar, but a protection in his very skin. Quirrell, sharing his soul with Voldemort, couldn’t bear to touch someone marked by something so good.
Loose Ends
Dumbledore also answers Harry’s other questions. The Stone has been destroyed. Nicolas Flamel and his wife have enough Elixir saved to put their affairs in order, and then they will die. Dumbledore says death is just the next great adventure for a well-organized mind.
Snape hated Harry’s father, James, but James once saved Snape’s life, and Snape has been protecting Harry to repay the debt. The Invisibility Cloak was James’s, and Dumbledore gave it back. Quirrell is gone, and Voldemort fled his body. Dumbledore warns that he’ll try again.
The House Cup
Then comes the end-of-year feast. Slytherin is set to win the House Cup for the seventh year running, and Gryffindor is in last place.
Dumbledore hands out last-minute points: fifty to Ron for the best-played game of chess, fifty to Hermione for cool logic in the face of fire, sixty to Harry for pure nerve and outstanding courage. That ties Gryffindor with Slytherin at four hundred and seventy two. And then, ten points to Neville, for the bravery it takes to stand up to your friends. Gryffindor wins.
The Last Page
Hagrid gives Harry a gift: a leather photo album full of wizard photos of his parents, which Hagrid collected by sending owls to their old school friends. Then it’s back to King’s Cross and the Dursleys.
The book ends with a wicked little joke. Harry tells Ron and Hermione that the Dursleys don’t know students aren’t allowed to use magic at home. He’s going to have a lot of fun this summer.
What It Sets Up
This ending sets up the entire series. Voldemort is alive and looking for a body. Harry has a connection to him through the scar. Snape is protecting Harry while openly hating him, a contradiction that pays off seven books later.
And the idea of a mother’s sacrifice as protection becomes central to the whole saga. On a first read it feels like a sweet bedtime moral. On a reread, it’s the foundation of everything.
My Take
I love this ending as a mystery. The red herring, Snape, is played perfectly. The clues to Quirrell are there from his first appearance, and the mirror solution is clever and fair.
The weakest part is the House Cup. Awarding the points in front of Slytherin, after their banners are already up, is a little cruel, and Dumbledore’s timing feels designed for a cheer. But Neville’s ten points? That one I’ll defend forever. Tell me in the comments: did you suspect Quirrell?
