After exams but before the end of term, Harry keeps feeling pain in his scar. He does not know what the pain means, but thinks it may mean that danger approaches. He asks Hagrid if the stranger with whom he played cards and from whom he won the dragon egg was interested in Fluffy; Hagrid says that the stranger was. In fact, Hagrid-who was intoxicated at the time, because the stranger kept buying him drinks-revealed to the stranger that Fluffy will fall asleep when he listens to music. Anxious to warn Professor Dumbledore, Harry learns from Professor McGonagall that the headmaster has been called away to London on urgent business by the Ministry of Magic. He tells McGonagall that someone will try to steal the Sorcerer's Stone. McGonagall is surprised that Harry knows about the Stone, but assures him that it is well-guarded. Harry resolves to try and get to the Stone before Snape can: "If Snape gets hold of the Stone, Voldemort's coming back!" He, Ron, and Hermione hide under the Invisibility Cloak and go to the third-floor corridor, only to find the door already open. Going through, Harry plays a flute to lull Fluffy to sleep. Once the three-headed dog is asleep, the three students go down through the trapdoor. They land in a Devil's Snare plant, which Hermione-who, fortunately, paid attention in Herbology class-remembers how to kill. Then, the students enter a chamber where winged keys fly overhead. Seeing the lock in the heavy wooden door at the chamber's other end, the three youngsters hop on nearby broomsticks to chase down a key that will fit its lock. Using his skills as a Quidditch Seeker, Harry manages to capture the right key. In the next chamber the students find a huge chessboard. Acting as the chess pieces, they play a living game of wizards' chess in which captured pieces are destroyed. As play progresses, it becomes apparent that-as often happens in chess-a piece must be sacrificed in order for Harry to win the game and cross the board to continue his quest for the Stone. Unfortunately, in this case, the "piece" that must be sacrificed is Ron. The white queen strikes Ron to the ground, knocking him unconscious, but the white king shortly resigns, and Harry and Hermione run on, hoping that Ron will be safe. The two realize that they have now survived Sprout's charm (the Devil's Snare), Flitwick's charm (the flying keys), McGonagall's charm (the living chess game), and must now face Snape's charm. In the next room, they find a large troll, but it is already on the floor, unconscious. In the room beyond that they discover seven different bottles: a logic puzzle. They must drink one of the potions in order to move on. There is only one swallow, however. Harry sends Hermione back for Ron. He drinks the potion and moves on to the next room, where he finds Professor Quirrell.
In this well-constructed and well-executed chapter, Rowling shows the teamwork of Harry, Hermione, and Ron. Each student draws on his or her particular gifts and strengths to enable Harry to reach the final room in which the Sorcerer's Stone is to be found. Ironically, however, the team's work as a group leads to their separation, and Harry-as befits the mythic hero on his quest-finds himself alone to face the final danger, the ultimate challenge. Joseph Campbell points out that mythic heroes must all make a solitary descent into darkness in order to achieve their quests: "There are then two possibilities . . . . [Either] the hero is swallowed and taken into the abyss to be later resurrected . . . . [or] the hero, on encountering the power of the dark, may overcome and kill it, as did Siegfried and St. George when they killed the dragon. But as Siegfried learned, he must then taste the dragon blood, in order to take to himself something of that dragon power" (The Power of Myth, p. 146). In other words, as readers come to the close of the chapter, they can expect that Harry's descent into darkness will not leave him unchanged, and that, true to mythic form, he may even find some of the darkness within himself. Fans of the entire series will note that the extent to which "darkness" resides within Harry is a preoccupation throughout the novels; each successive book reveals an apparently closer connection between Harry and Voldemort, building on something as seemingly simple as the revelation in this first novel that Harry and the Dark Lord both wield the same kind of wand.