Harry Potter first comes across the name “Half-Blood Prince” in his sixth year at Hogwarts while using a borrowed Potions textbook. This old textbook is filled with handwritten notes and new spells signed by the mysterious “Half-Blood Prince.” As Harry relies more and more on the Half-Blood Prince’s book, he becomes determined to uncover the identity of this brilliant former Hogwarts student. After much speculation and several reveals throughout the story, Harry finally discovers that his Potions professor Severus Snape is the Half-Blood Prince.
The Half-Blood Prince’s Book
It all began when Harry couldn’t afford his own copy of Advanced Potion Making before starting his sixth year. Professor Slughorn, the new Potions master, allows Harry to take a spare text from the supply cabinet. Harry grabs a tattered, graffiti-covered book once belonging to a student known only as “the Half-Blood Prince.” Inside are all kinds of extra notes and new tips that help Harry excel at Potions for the first time. There are even original spells created by the Prince, like one called Levicorpus that dangles people upside-down. Thanks to this magical book, Potions becomes Harry’s best subject.
Naturally, Harry develops an intense fascination with discovering the identity of this gifted student. He becomes convinced that if he can track down the Half-Blood Prince, he can learn more advanced magic from him. The only clues to start with are the book’s creative spells and advice, all signed “H.B.P.” Harry asks if anyone recognizes that initialed nickname, but no one does. He starts asking older students like prefects, as they may have gone to Hogwarts with the Half-Blood Prince. But for most of the book, the Prince’s identity remains a baffling mystery.
Harry’s Theories on the Half-Blood Prince
With Hermione’s help, Harry researches genealogy records of past Hogwarts students, searching for likely “half-blood” candidates who could be the infamous Prince. They consider students with surnames like Pringle or Princewell, but have little luck tracking down solid leads. Harry strongly believes the Prince must be male, as girls were less likely to get a Potions education in old-fashioned times.
He thinks maybe his father James Potter or godfather Sirius Black knew the anonymous student back in the day, since they also created special spells. But much to Harry’s frustration, no one seems able to put a name to the initials. For a while, Harry suspects his Potions rival Draco Malfoy’s father Lucius, or even Voldemort himself when he was a student named Tom Riddle. But the evidence doesn’t quite add up for any student. Without the true Half-Blood Prince’s identity, Harry can’t learn more complex magic.
Harry Learns Advanced Spells
While the Prince’s identity remains uncertain, Harry continues benefitting from his old Potions book. He excels in Slughorn’s class and impresses the new professor with the Prince’s signature recipes and experiments. Harry even wins a special bottle of Felix Felicis luck potion by following the Prince’s suggestions.
In addition to Potions tips, the Prince’s book contains many invented spells that capture Harry’s interest. These include Levicorpus for hoisting people up by their ankles, Langlock for gluing someone’s tongue to the roof of their mouth, and Muffliato for filling people’s ears with static to block conversations. The most impressive Prince spell is Sectumsempra, labeled “For Enemies.” When Harry later uses it on Draco without knowing its effects, it badly slashes and nearly kills the Slytherin student. This offers the first clue that the Prince may have had a darker side.
The Potions Book’s Half-Blood Prince
After the Sectumsempra incident, Harry tries to learn more about the dangerous spell, but can’t find it in the Hogwarts library. Hermione surmises that the Half-Blood Prince created the nasty curse while at school. Harry starts to reconsider using the Potions book since the unknown Prince clearly dabbled in the Dark Arts and may have been up to no good.
But Harry feels he needs to keep the book to excel at Potions andmaybe uncover more about the Prince’s identity. He focuses on deciphering small clues like the scribbled handwriting, types of spells created, and clever improvements made to potion recipes. Harry even starts thinking maybe Snape could be the Prince, since he’s talented at Potions too. But Snape is described as full wizard blood, not the half-blood that the mystery student’s nickname implies.
Draco’s Secret Mission
Separate from the Half-Blood Prince mystery, Harry remains suspicious of his Slytherin rival Draco Malfoy in their sixth year. Draco is often seen whispering with his gang and disappearing from the Marauder’s Map. Harry believes Draco joined the Death Eaters and is up to no good. When he confronts Malfoy, Draco refuses to roll up his sleeves, making Harry think he’s hiding the Dark Mark.
Harry, Ron and Hermione take turns secretly following Malfoy using the Invisibility Cloak, an endeavor they nickname “The Malfoy Project.” They overhear him muttering sinister plans and being reprimanded by Snape for neglecting his schoolwork. But they still have no concrete evidence of what exactly Draco is plotting.
Draco’s Vanishing Cabinet
The trio finally discovers Draco has been repairing an old Vanishing Cabinet in the Room of Requirement, its mate located in Borgin and Burkes shop. Harry alarms the Order of the Phoenix that the passage may allow Death Eaters to enter Hogwarts. As extra security, Order members patrol the halls undercover as aurors or professors.
Sure enough, at the end of the book Draco successfully transports Death Eaters into the school through the linked Vanishing Cabinet. This allows the invasion in which Dumbledore is tragically killed. But due to Harry’s early warnings, life-saving backup arrives from the Order just in time to prevent further casualties.
Snape Revealed as the Half-Blood Prince
In the climax of Harry Potter and the Half-Blood Prince, Dumbledore and Harry set out to search for one of Voldemort’s final hidden Horcruxes. Their perilous mission leads them to a cave by the sea. Weakened by a potion protecting the locket Horcrux, Dumbledore asks Harry to fetch Snape’s help immediately upon their return to Hogwarts.
But before Snape can assist, the Death Eaters Draco smuggled attack the unguarded school. As they battle Order members and students, Dumbledore is cornered in the Astronomy Tower by Draco, who is attempting to fulfill Voldemort’s orders to kill the Hogwarts headmaster.
Snape Arrives in the Tower
When Snape suddenly arrives on the tower as well, Draco lowers his wand, no longer able to commit murder. Snape then takes over and performs the Killing Curse on Dumbledore himself. While a shocked Harry watches hidden from below, Snape reveals himself as the Half-Blood Prince – the former student who once wrote in the old Potions book now used by Harry.
As he flees Hogwarts with Draco and the other Death Eaters, Snape calls himself the Prince and gives orders to retreat. All the pieces finally click into place for Harry, who now knows Snape is both a traitor and the brilliant Half-Blood Prince who helped him all year. He is enraged at Snape’s betrayal after Dumbledore unwaveringly trusted him.
Clues Pointing to Snape as the Prince
Looking back, subtle clues indicated Snape may have been the Prince:
- Snape excelled at Potions as a student, enough to later teach the class
- He was skilled at inventing new jinxes and curses as a teen
- His mother’s surname was Prince before becoming Eileen Snape when she married
- Being half-blood from a Muggle father and witch mother fit the nickname
In addition, Snape had the Dark Arts interest and cunning ambition to craft spells like Levicorpus and Sectumsempra while a student. He may have hoped to gain favor or protection as a half-blood Slytherin by using Dark Magic. Dumbledore once referred to Snape knowing more hexes as a first-year than most seventh-years.
Why Snape Concealed His Identity
Once a Death Eater, Snape spent years spying on Voldemort for Dumbledore and working to protect Harry, despite his personal grudges. He likely wanted to keep his brilliant student achievements as the Half-Blood Prince private so that his loyalty to Dumbledore would not be questioned by fellow Death Eaters.
Snape probably would have been furious and embarrassed for students like Harry to know he devised those spells and potion tips as a bullied, over-achieving teen. Discovering that personal part of his past may have compromised Snape’s undercover position as well.
Significance of Revealing Snape as the Prince
The dramatic reveal that Severus Snape was the Half-Blood Prince all along served several key purposes in the Harry Potter story:
- It exposed Snape’s secret past as an inventive, talented student and potion-maker, giving insight into his later skills and interests as a professor
- It showed even as a student, Snape was fascinated by the Dark Arts and creating his own deadly spells
- It highlighted how he hid his identity and true loyalty due to being a double agent
- It connected back to the book that helped Harry so much during the school year
- It emphasized Snape’s betrayal by murdering the trusting Dumbledore who believed in him
Most critically, proving Snape authored the Potions book and its disturbing magic forced an emotional reckoning in Harry. He could no longer see Snape as merely a mean, unfair teacher – but rather a dangerous, two-faced killer secretly obsessed with the Dark Arts since childhood.
This discovery fueled Harry’s commitment to defeating the Death Eaters and Snape, whom he felt betrayed everyone by murdering the great wizard who always vouched for his innocence.
Conclusion
Throughout Harry Potter and the Half-Blood Prince, the identity of the brilliant, mysterious student who owned Harry’s Potions book remains a central mystery. As Harry relies more and more on the Prince’s ingenious tips and spells, he becomes determined to learn the truth. Major events like Draco’s mission and Dumbledore’s death ultimately lead to Snape revealing himself as the Half-Blood Prince in the Astronomy Tower.
Looking back, small clues hinted Snape was the Prince all along. But this major reveal provided both answers and emotional impact at the climax, exposing Snape’s secret obsession with the Dark Arts even as a student. Most critically, proving Snape authored the helpful textbook gave Harry a personal sense of betrayal that deeply influenced his resolve to defeat the Death Eaters.