Harry and Ron are angry at Hermione. Wood seeks Harry to find out if he will be able to play in the next game. Harry has his first Anti-Dementor lesson from Professor Lupin. Lupin uses a Boggart which will turn into a Dementor. He teaches Harry the Patronus Charm, ¤ Expecto Patronum. A Patronus is a type of guardian which will act as a shield between him and the Dementor. Harry tries it on the Boggart, shape-shifted as a Dementor. Inside his head, he hears the last moments of his mother's life again. He loses consiousness and regains it again, Lupin giving him Chocolate Frogs. He tries again, this time he hears his father also. Lupin tells Harry he used to be friends with his father. Harry has another go and this time he's able to keep stand up to the Dementor. Lupin charms it with a ¤ Riddikulus and puts the Boggart back into a packing case.
Slytherin had beaten Ravenclaw at Quidditch, meaning Gryffindor still has a good shot at the Cup. Wood increases the team practices. Besides his Anti-Dementor lessons, Harry has little time left for homework. Hermione also seems to be strained by all the classes she's taking. Ron wonders how she has manages to attend all of her classes. He had heard her talking to Arithmancy Professor Vector about yesterday's lesson, but could not understand how she could have been there because she was with them in Care of Magical Creatures class. In addition to that, Ernie McMillan had told him that hermione never missed a Muggle Studies class, although most of these classes are at the same time.
Time passes and Harry still hasn't got his broom back. He is told it has been tested for the usual curses but it still has to be cleared for a Hurling Hex. Anti-Dementor lessons have not shown much more progress. Lupin tells Harry about the Dementors' Kiss which they use to suck out the soul of a person. He tells Harry that this will be Black's fate when he is caught, as the Dementors have been given permision by the Ministry. Harry get's his broom back from Professor McGonagall. Together with Ron he sets off to the common room to make up with Hermione. Neville is at the entrance. He lost the passwords after having written them down not to forget them. Harry says the password "Oddsbodikins" and they enter the common room. Everybody has gathered to admire his new broom. After a while, Ron offers to take it upstairs. While Harry is talking with Hermione, there's a yell and Ron comes down. Holding a bloodstained sheet, he tells them Scabbers is gone and he found ginger cat hairs in his room
- Daniel Radcliffe - Harry Potter
- Emma Watson - Hermione Granger
- Rupert Grint - Ron Weasley
- Sean Biggerstaff - Oliver Wood
- Robbie Coltrane - Rubeus Hagrid
- Emma Thompson - Sybill Trelawney
- David Thewlis - Remus Lupin
- Geraldine Somerville - Lily Potter (VOICE)
- Ralph Fiennes - Lord Voldemort (VOICE)
- Adrian Rawlins - James Potter (VOICE)
- Maggie Smith - Minerva McGonagall
- Matthew Lewis - Neville Longbottom
- Paul Whitehouse - Sir Cadogan