Harry Potter casts his first Patronus Charm

Harry Potter casts his first Patronus Charm during a private lesson with Remus Lupin in the History of Magic classroom, using a Boggart transformed into a Dementor as a practice target. The attempt is only partially successful, producing a wisp of silvery gas rather than a fully formed guardian, and it triggers a vivid auditory flashback of his mother Lily Potter's murder by Lord Voldemort. This first effort establishes the central difficulty of the charm for Harry: the need to concentrate on a powerful happy memory while the Dementor forces him to relive his parents' deaths.

Setting and Preparation

The lesson takes place on a Thursday evening at eight o'clock in the History of Magic classroom, which is dark and empty when Harry arrives. He lights the lamps with his wand and waits only five minutes before Professor Lupin enters, carrying a large packing case. Lupin explains that he has been combing the castle since Tuesday and found a Boggart lurking inside Argus Filch's filing cabinet. The Boggart will transform into a Dementor when it sees Harry, making it the nearest substitute for a real one they can safely use. Lupin stores the Boggart in a cupboard under his desk when not in use. He describes the Patronus Charm as highly advanced magic, well beyond Ordinary Wizarding Level, and warns Harry that many qualified wizards have difficulty with it. The Patronus, he explains, is a kind of anti-Dementor, a guardian that acts as a shield, a projection of hope, happiness, and the desire to survive—the very things a Dementor feeds upon.

The First Attempt

Harry casts about for a suitable happy memory to concentrate on. Nothing from his life at the Dursleys' will do, so he settles on the moment he first rode a broomstick, trying to recall the wonderful, soaring sensation in his stomach. Lupin instructs him in the incantation, clearing his throat and saying, "Expecto patronum!" Harry repeats the words under his breath, stumbling over the pronunciation at first, correcting himself from "patrono" to "patronum." When he speaks the incantation aloud, something whooshes suddenly from the end of his wand—a wisp of silvery gas. Harry is excited, but Lupin calmly tells him to prepare for the real test. Lupin grasps the lid of the packing case and pulls. A Dementor rises slowly from the box, its hooded face turned toward Harry, one glistening, scabbed hand gripping its cloak. The lamps around the classroom flicker and go out. The Dementor steps from the box and begins to sweep silently toward Harry, drawing a deep, rattling breath. A wave of piercing cold breaks over him. Harry yells, "Expecto patronum! Expecto patronum! Expecto—" but the classroom and the Dementor dissolve. He is falling again through thick white fog, and his mother's voice is louder than ever, echoing inside his head: "Not Harry! Not Harry! Please—I'll do anything—" followed by Voldemort's command to stand aside. Harry jerks back to life lying flat on his back on the floor, the classroom lamps alight again. He sits up, feeling cold sweat trickling down behind his glasses, and mutters an apology.

The Second Attempt and a New Memory

Lupin gives Harry a Chocolate Frog and tells him to eat it before they try again, saying he didn't expect success on the first attempt and would have been astounded if Harry had managed it. Harry mutters that it is getting worse—he could hear his mother louder that time, and Voldemort as well. Lupin looks paler than usual and offers to stop, but Harry insists on continuing, saying he cannot afford to fall off his broom again if Dementors appear at the Quidditch match against Ravenclaw. Lupin suggests Harry select another happy memory, as the first one did not seem strong enough. Harry thinks hard and decides on the feeling when Gryffindor won the House Championship the previous year. He grips his wand tightly and takes up his position in the middle of the classroom. Lupin pulls off the lid again. The room goes icily cold and dark once more. The Dementor glides forward, drawing its breath, one rotting hand extending toward Harry. Harry yells, "Expecto patronum! Expecto patronum! Expecto Pat—" but white fog obscures his senses. This time he hears a new voice—a man's voice, shouting, panicking: "Lily, take Harry and go! It's him! Go! Run! I'll hold him off—" followed by the sounds of someone stumbling from a room, a door bursting open, and a cackle of high-pitched laughter. Lupin taps Harry hard on the face to wake him. This time it is a minute before Harry understands why he is lying on the dusty classroom floor. He realizes he has heard his father James Potter's voice for the first time, trying to take on Voldemort himself to give his mother time to run. There are tears on his face mingling with the sweat; he bends his face low, wiping them off on his robes, pretending to do up his shoelace so Lupin will not see.

The Third Attempt and a Partial Success

Lupin, speaking in a strange voice, confirms that he knew James Potter as a friend at Hogwarts and suggests they stop for the night, calling the charm ridiculously advanced. Harry refuses, saying he needs one more go because he is not thinking of happy enough things. He racks his brains for a really, really happy memory and settles on the moment he first found out he was a wizard and would be leaving the Dursleys for Hogwarts. Concentrating very hard on how he had felt when he realized he would be leaving Privet Drive, Harry gets to his feet and faces the packing case once more. Lupin, looking as though he is acting against his better judgment, pulls off the lid for the third time. The Dementor rises; the room falls cold and dark. Harry bellows, "EXPECTO PATRONUM! EXPECTO PATRONUM! EXPECTO PATRONUM!" The screaming inside his head starts again, but this time it sounds as though it is coming from a badly tuned radio—softer and louder and softer again. He can still see the Dementor. It has halted. Then a huge, silver shadow comes bursting from the end of Harry's wand, hovering between him and the Dementor. Though his legs feel like water, he remains on his feet. Lupin springs forward, shouting "Riddikulus!" There is a loud crack, and Harry's cloudy Patronus vanishes along with the Dementor. Harry sinks into a chair, feeling as exhausted as if he had just run a mile, his legs shaking. Lupin strides over, calling the result excellent and saying it is definitely a start. Harry asks for another go, but Lupin refuses, saying he has had enough for one night. He hands Harry a large bar of Honeydukes' best chocolate and tells him to eat the lot, or Madam Pomfrey will be after his blood. They agree to meet again at the same time next week.

Aftermath and Significance

Harry leaves the classroom, walking along the corridor and around a corner, then takes a detour behind a suit of armor and sinks down on its plinth to finish his chocolate. He feels drained and strangely empty, even though he is full of chocolate. He realizes that terrible though it is to hear his parents' last moments replayed inside his head, these are the only times he has heard their voices since he was a very small child. He sternly tells himself they are dead and that listening to echoes of them will not bring them back, and that he had better get a grip on himself if he wants the Quidditch Cup. The first lesson establishes the fundamental challenge of the Patronus Charm for Harry: the very memories he must draw upon to produce the charm are the ones the Dementor forces him to relive, creating a painful paradox that he must learn to overcome in subsequent sessions.