The final chapter of the first book has a lot going on in it. The main event is depicted well in the film; it only loses some of the details.

This chapter begins with Harry realizing it’s Professor Quirrell in the last chamber, not Professor Snape as he expected.

“But Snape tried to kill me!”
“No, no, no. I tried to kill you. Your friend Miss Granger accidentally knocked me over as she rushed to set fire to Snape at that Quidditch match. She broke my eye contact with you. Another few seconds and I’d have got you off that broom. I’d have managed it before then if Snape hadn’t been muttering a countercurse, trying to save you.”

Ah yes, the deeper story of the complicated person Severus Snape turns out to be.

Quirrell binds Harry with ropes and tries to figure out where the Sorcerer’s Stone is. In the chamber is only the Mirror of Erised. He can see himself giving the stone “to his master” but can’t figure out how to get it.

“But Snape always seemed to hate me so much.”
“Oh, he does,” said Quirrell casually, “heavens, yes. He was at Hogwarts with your father, didn’t you know? They loathed each other. But he never wanted you dead.

This is sort of a “Scooby-Doo” moment where Quirrell reveals everything to Harry. Harry is doing this because keeping him talking is the only way he can think of to distract him from finding the Sorcerer’s Stone.

“He is with me wherever I go,” said Quirrell quietly. “I met him when I traveled around the world. A foolish young man I was then, full of ridiculous ideas about good and evil. Lord Voldemort showed me how wrong I was. There is no good and evil, there is only power, and those too weak to seek it… Since then, I have served him faithfully, although I have let him down many times. He has had to be very hard on me.” Quirrell shivered suddenly. “He does not forgive mistakes easily. When I failed to steal the stone from Gringotts, he was most displeased. He punished me… decided he would have to keep a closer watch on me…”

The question I have is whether Quirrell was truly evil or whether he was weak and Voldemort took advantage of that. It seems to be the case with most nefarious people that they find people who are weak to follow them, and use them until they are no longer needed. Is that the case with Quirrell? Did he willingly accept Voldemort into him, or was he merely traveling and happened upon what was left of the Dark Lord, and he took advantage of his weak character? Was Quirrell someone who was bullied all his life – much like Snape – who was looking for a place to belong and “get back” at others? There’s so much more here that can be examined and just isn’t answered. There could be a prequel book about Quirrell and his travels and encountering Voldemort.

“I don’t understand… is the Stone inside the mirror? Should I break it?”
Harry’s mind was racing.
What I want more than anything else in the world at the moment, he thought, is to find the Stone before Quirrell does. So if I look in the mirror, I should see myself finding it — which means I’ll see where it’s hidden! But how can I look without Quirrell realizing what I’m up to?

Getting into Harry’s thoughts is a bit of detail that’s missing from the films.

He clapped his hands once, and the ropes binding Harry fell off. Harry got slowly to his feet.
“Come here,” Quirrell repeated. “Look in the mirror and tell me what you see.”
Harry walked toward him.
I must lie, he thought desperately. I must look and lie about what I see, that’s all.

Harry, Quirrell, and Voldemort argue more, as in the film, and Voldemort knows Harry has somehow gotten the Stone in his pocket. However, when Quirrell tries to take it from him he finds he cannot touch Harry without his skin burning. Harry tries to hold onto him, preventing him from being able to cast a curse, and eventually loses consciousness, his last thought being Quirrell’s arm being ripped away from where Harry is holding onto it.

Harry awakens in the hospital wing of Hogwarts.

“Good afternoon, Harry,” said Dumbledore.
Harry stared at him. Then he remembered: “Sir! The Stone! It was Quirrell! He’s got the Stone! Sir, quick —”
“Calm yourself, dear boy, you are a little behind the times,” said Dumbledore. “Quirrell does not have the Stone.”

Harry is in the hospital wing, as it is at the end of the film.

“Not the Stone, boy, you — the effort involved nearly killed you. For one terrible moment there, I was afraid it had. As for the Stone, it has been destroyed.”
“Destroyed?” said Harry blankly. “But your friend — Nicolas Flamel —”
“Oh, you know about Nicolas?” said Dumbledore, sounding quite delighted. “You did do the thing properly, didn’t you? Well, Nicolas and I have had a little chat, and agreed it’s all for the best.”

I like this exchange. Dumbledore is more worried about Harry than the Stone, even knowing what could have happened had Voldemort succeeded in getting it.

“Yes, sir. Well, Voldemort’s going to try other ways of coming back, isn’t he? I mean, he hasn’t gone, has he?”
“No, Harry, he has not. He is still out there somewhere, perhaps looking for another body to share… not being truly alive, he cannot be killed. He left Quirrell to die; he shows just as little mercy to his followers as his enemies. Nevertheless, Harry, while you may only have delayed his return to power, it will merely take someone else who is prepared to fight what seems a losing battle next time — and if he is delayed again, and again, why, he may never return to power.”

Yes, to an 11-year-old, this is a good response. Of course, it will change later on.

Dumbledore now became very interested in a bird out on the windowsill, which gave Harry time to dry his eyes on the sheet. When he had found his voice again, Harry said, “And the invisibility cloak — do you know who sent it to me?”

“Ah — your father happened to leave it in my possession, and I thought you might like it.” Dumbledore’s eyes twinkled. “Useful things… your father used it mainly for sneaking off to the kitchens to steal food when he was here.”

I knew it! They never say in the films who sent it to Harry.

“Yes, him — Quirrell said he hates me because he hated my father. Is that true?”
“Well, they did rather detest each other. Not unlike yourself and Mr. Malfoy. And then, your father did something Snape could never forgive.”
“What?”
“He saved his life.”
“What?”

Ah yes, another detail that didn’t make it into the film. We learn later on that James and his friends bullied Severus at the school, but apparently James was a very complex person, like most of us are.

“Yes…” said Dumbledore dreamily. “Funny, the way people’s minds work, isn’t it? Professor Snape couldn’t bear being in your father’s debt… I do believe he worked so hard to protect you this year because he felt that would make him and your father even. Then he could go back to hating your father’s memory in peace…”

Well, I think there’s more to it than that and it involves the love Snape had for Lily, but that’s a good answer to an 11-year-old who probably still thinks all that romantic stuff is icky.

Dumbledore confirms to Harry that he was able to retrieve the Stone from the Mirror because the spell Dumbledore used was that it would only appear to someone who wanted to find the Stone but wasn’t going to use the Stone. It’s sort of glossed over that this was Dumbledore’s spell.

After Dumbledore leaves, Harry convinces Madame Pomfrey to allow Ron and Hermoine to visit. He tells them everything that happened (despite Madame Pomfrey saying they could only stay for 5 minutes).

“No, it isn’t,” said Harry thoughtfully. “He’s a funny man, Dumbledore. I think he sort of wanted to give me a chance. I think he knows more or less everything that goes on here, you know. I reckon he had a pretty good idea we were going to try, and instead of stopping us, he just taught us enough to help. I don’t think it was an accident he let me find out how the mirror worked. It’s almost like he thought I had the right to face Voldemort if I could…

Very insightful. Of course, Hermoine is right, Harry could have been killed and that’s a risk Dumbledore took when he put this situation in front of Harry and waited to see where he’d take it.

The next day, before Harry is released, Hagrid comes to visit.

“It’s — all — my — ruddy — fault!” he sobbed, his face in his hands. “I told the evil git how ter get past Fluffy! I told him! It was the only thing he didn’t know, an’ I told him! Yeh could’ve died! All fer a dragon egg! I’ll never drink again! I should be chucked out an’ made ter live as a Muggle!”

It’s nice that Hagrid takes responsibility for some of what happened. He’s just such an innocent soul that he misses a lot of the negativity in the world.

“Nah. Dumbledore gave me the day off yesterday ter fix it. ‘course, he shoulda sacked me instead — anyway, got yeh this…”
It seemed to be a handsome, leather-covered book. Harry opened it curiously. It was full of wizard photographs. Smiling and waving at him from every page were his mother and father.
“Sent owls off ter all yer parents’ old school friends, askin’ fer photos… knew yeh didn’ have any… d’yeh like it?”
Harry couldn’t speak, but Hagrid understood.

This would have been nice to see in the film.

The next scene is the end of year feast. This is depicted well in the film, with only a few details missing. The points Dumbledore awards the Gryffindor students at the last minute are a little different than what was in the film, but it all works out the same.

Harry had almost forgotten that the exam results were still to come, but come they did. To their great surprise, both he and Ron passed with good marks; Hermione, of course, had the best grades of the first years. Even Neville scraped through, his good Herbology mark making up for his abysmal Potions one. They had hoped that Goyle, who was almost as stupid as he was mean, might be thrown out, but he had passed, too. It was a shame, but as Ron said, you couldn’t have everything in life.

More of the real things students are concerned about; passing their classes and not being able to stay in the school. It was never even really talked about in the first film.

The scene of them leaving the school is expanded on much more in the book, including arriving back in London at Platform 9 3/4.

It took quite a while for them all to get off the platform. A wizened old guard was up by the ticket barrier, letting them go through the gate in twos and threes so they didn’t attract attention by all bursting out of a solid wall at once and alarming the Muggles.

The scene where Ron’s parents meet Harry’s Uncle Vernon and Aunt Petunia is missing. Vernon is as unpleasant to them as he is to Harry, instead of trying to present a happy front to the outside world. I’m wondering why he even bothered to come to the station and pick Harry up.

“Oh, I will,” said Harry, and they were surprised at the grin that was spreading over his face.
“They don’t know we’re not allowed to use magic at home. I’m going to have a lot of fun with Dudley this summer…”

So it’s not Hagrid that says this, but Harry’s own idea!

The book wraps up not missing a terrible amount of detail. Overall the biggest loss is Peeves. The first film overall was adapted very well from the book.

Previous chapter (link): Harry Potter and the Sorcerer’s (Philosopher’s) Stone Chapter 16: Through the Trapdoor