Slughorn's Social Circle
Harry Potter and the Half-Blood PrinceProfessor Slughorn forms a club of promising students, using them to network and curry favor, while Harry tries to extract a crucial memory.
increasing
Bearing strength in each event
decreasing
The Slug Club Invitations

The First Gathering
The Invitations
On the Hogwarts Express, Horace Slughorn invites selected students to his compartment for lunch. The guests include Harry Potter, Neville Longbottom, Ginny Weasley, Blaise Zabini, and others. Slughorn is clearly interested in those with famous relatives or connections.
The Networking
Slughorn asks each student about their family and achievements. He is particularly interested in Harry, the 'Chosen One'. He also pumps Neville about his parents and Ginny about her hexing skills. The atmosphere is one of favoritism and manipulation.
Harry's Discomfort
Harry feels uncomfortable with Slughorn's obvious favoritism. He learns that the 'Slug Club' is a network of former students who have become influential. Slughorn uses his connections to gain benefits, such as free tickets and gifts from his former students.
The Christmas Party

The Slug Club Party
The Event
Slughorn hosts a Christmas party in his office, decorated with festive magic. The guest list includes Harry, Hermione Granger, Cormac McLaggen, and others. Harry is forced to attend, but he uses the opportunity to try to get the memory from Slughorn.
The Party Dynamics
At the party, Harry observes Slughorn's interactions with his favorites. He also sees Draco Malfoy trying to gatecrash, and Severus Snape confronts Malfoy. Harry overhears a crucial conversation between Snape and Malfoy, strengthening his suspicions.
The Failed Attempt
Harry attempts to ask Slughorn about the Horcrux memory, but Slughorn is evasive and leaves quickly. The party ends with Harry feeling frustrated. He realizes that he needs a different approach to obtain the memory.
The Successful Extraction

The Breakthrough
The Opportunity
Harry uses Felix Felicis to create a lucky opportunity. He meets Slughorn in the vegetable patch and convinces him to attend Aragog's burial. During the gathering, Harry appeals to Slughorn's fondness for Lily Potter and his guilt about the memory.
The Persuasion
Over drinks, Harry emotionally recounts his mother's death and Slughorn's role in her story. He tells Slughorn that he is the Chosen One and needs the memory to defeat Voldemort. Slughorn, moved and ashamed, finally extracts the true memory and gives it to Harry.
The Result
Harry obtains the memory and delivers it to Dumbledore. The memory reveals that Voldemort intended to create multiple Horcruxes, confirming Dumbledore's theory. This is a turning point in the fight against Voldemort.
early September, on the Hogwarts Express
late December, during the Christmas holidays
late March, after Ron's poisoning