Ginny Weasley's Bewitchment: The movie opens with Ginny Weasley mysteriously bewitched by a cursed diary in her first year at Hogwarts. Harry Potter witnesses her distress and seeks to uncover the truth behind her possession, laying the groundwork for the exploration of Tom Riddle's past.
Harry and Dumbledore's Meeting at Privet Drive: Harry Potter receives an unusual visitor, Professor Albus Dumbledore, at Privet Drive. Together, they discuss critical developments, including Voldemort's return and the significance of Horace Slughorn's memories. This sets the tone for their investigation into Voldemort's past and his connection to Slughorn.
Potions Class with Professor Slughorn: Harry Potter begins attending Potions class with Professor Horace Slughorn, who encourages his students to use unconventional methods in potion-making. Harry discovers an old textbook once belonging to "The Half-Blood Prince," which contains valuable annotations and instructions that help him excel in the subject.
Horace Slughorn's Invitation to the Slug Club: Harry Potter is invited to join the exclusive Slug Club, a group of influential students and individuals that Professor Slughorn selects. This provides Harry with an opportunity to acquire valuable information and interact with key characters, including Horace Slughorn himself.
Ron's Unlucky Spell: Ron Weasley becomes the target of an unfortunate spell during a lesson with Professor Flitwick, resulting in his face being permanently disfigured. This incident highlights Ron's insecurities and adds depth to his character's journey.
These initial events introduce critical character conflicts, mysteries to solve, and relationship dynamics, setting the course for the subsequent developments and challenges that Harry Potter and his friends encounter throughout the film.