Harry Potter and the Half-Blood Prince characters

First appears in chapter 3

Sixteen and, since Voldemort's return became public, a celebrated figure rather than a doubted one. Grieving his godfather Sirius and trusted by Dumbledore with private lessons, Harry spends the year both learning Voldemort's history and obsessively convinced that Draco Malfoy has become a servant of the enemy, a suspicion nobody else takes seriously.

First appears in chapter 5

Harry's best friend, now a Gryffindor Quidditch keeper and tangled up in the awkward romances of their sixth year. His clumsy relationship with a classmate and his prickliness with Hermione strain the friends' good humour, but he stays firmly at Harry's side as the danger grows.

First appears in chapter 6

Harry and Ron's brilliant friend, whose feelings for Ron and jealousy over his romance run through the year alongside her usual sharp research. She is sceptical of Harry's fixation on Draco and uneasy about the mysterious old textbook that is making Harry so good at potions.

First appears in chapter 3

The Hogwarts headmaster, who collects Harry personally this summer and begins meeting him privately to explore Voldemort's past through gathered memories. His right hand is mysteriously blackened and withered, and he is more openly mortal and more determined than ever, working toward a secret plan to bring about Voldemort's downfall.

First appears in chapter 2

The Potions master, who at last gains the Defence Against the Dark Arts post he has long wanted. In the book's opening he makes an Unbreakable Vow to Narcissa Malfoy, swearing to protect and assist her son Draco and, if Draco fails, to finish a task himself, though the nature of that task is kept hidden.

First appears in chapter 6

Harry's rival, withdrawn and frightened this year beneath his usual sneer. With his father imprisoned after the Ministry battle, Harry is convinced Voldemort has set him some grim task and, watching him slip away to the castle's forgotten corners, that Draco is now a Death Eater working from within the school.

First appears in chapter 5

Ron's spirited younger sister, now a popular and confident girl and a talented Quidditch player. Over the year Harry finds his feelings for her deepening into something he has to keep pushing down, complicated by her being his best friend's sister.

First appears in chapter 4

A genial, well-connected retired Hogwarts teacher whom Dumbledore coaxes back to teach Potions. He loves to collect promising and famous students and cultivate their favour, and he carries a guilty secret from his past that Dumbledore badly needs Harry to draw out of him.

First appears in chapter 2

Draco's mother, desperate to protect her son now that her husband is imprisoned and Voldemort has set Draco a dangerous task. Defying the Dark Lord's wishes, she secretly seeks out Snape and begs his help, binding him to a magical oath to shield her boy.

First appears in chapter 2

Narcissa's sister and a fanatically loyal servant of Voldemort. Distrustful and cruel, she accompanies Narcissa to Snape's house and tries to catch him out in disloyalty, doubting that he truly serves the Dark Lord.

Also known as Tom Riddle

First appears in chapter 10

The dark lord, now openly returned and terrorizing both wizards and Muggles. This year Dumbledore shares gathered memories that trace his history, from his birth as the orphan Tom Riddle, through a cold and manipulative boyhood, to his transformation into Voldemort, all in search of the secret to how he has cheated death.

First appears in chapter 9

The unknown former owner of a second-hand Potions textbook Harry is given, who filled its margins with improved instructions and invented spells and signed it 'the Half-Blood Prince.' The notes make Harry brilliant at potions and fascinate him, but he cannot discover who the Prince was, and some of the scrawled spells prove darker than they first seem.