Fake Horcrux Locket
The Fake Horcrux Locket is a decoy object that derails the central quest of Harry Potter and the Half-Blood Prince at its most critical moment. Left in the stone basin on the island in the cave by the mysterious R.A.B., it replaces the true Horcrux that Dumbledore and Harry had traveled so far to retrieve. Its discovery, immediately after Dumbledore's murder, transforms the entire mission from a completed victory into a hollow defeat, forcing Harry to confront the fact that Dumbledore's agonizing sacrifice had been for nothing and that the hunt for Voldemort's remaining soul fragments must continue without the one they had risked everything to obtain.
Discovery and Immediate Context
After Dumbledore's body falls from the Astronomy Tower, Harry kneels beside him and notices the locket that had fallen from the headmaster's pocket, likely dislodged by the force of the impact. As he picks it up, he immediately senses that something is wrong. The object in his hands is neither as large as the locket he had seen in the Pensieve during the memory of Hepzibah Smith, nor does it bear any markings — there is no sign of the ornate serpentine S that should identify it as Salazar Slytherin's relic. Inside, instead of a portrait or any magical compartment, there is only a scrap of folded parchment wedged tightly into the space where the true Horcrux should have been.
The Note from R.A.B.
Harry pulls out the fragment of parchment and reads it by the light of the many wands now lit behind him. The note is addressed to the Dark Lord and written by someone who signs themselves R.A.B. It states that the writer knows they will be dead long before Voldemort reads the message, but wants him to know that it was they who discovered his secret. They have stolen the real Horcrux and intend to destroy it as soon as they can. The note concludes with the writer facing death in the hope that when Voldemort meets his match, he will be mortal once more. Harry, in his state of shock and grief, neither knows nor cares what the message means at that moment. Only one thing registers: this is not a Horcrux.
Consequences for the Quest
The revelation that the locket is a fake has devastating implications for everything Dumbledore and Harry had endured in the cave. Dumbledore had weakened himself by drinking the terrible potion that forced him to relive his worst memories and fears, screaming and begging for death, all to reach the basin and retrieve what he believed was one of Voldemort's Horcruxes. The Inferi had risen from the black lake, and only Dumbledore's desperate conjuration of a ring of protective fire had saved them. All of that suffering, all of that risk, had been for a decoy. The true Horcrux remains out there, hidden by an unknown person whose identity and motives are a complete mystery.
Thematic Significance
The Fake Horcrux Locket functions as a brutal narrative reversal, underscoring the theme that the fight against Voldemort is never straightforward and that even the greatest wizard can be outmaneuvered. It also introduces the figure of R.A.B., a character who, like Dumbledore and Harry, was willing to sacrifice everything to undermine Voldemort's immortality. The locket becomes a physical symbol of the unfinished nature of Harry's mission: he carries it with him everywhere after Dumbledore's death, not as a talisman, but as a constant reminder of what the quest has cost and how much remains to be done. The initials R.A.B. will later prove to be Regulus Black, Sirius's younger brother, who had turned against Voldemort and died in the attempt to destroy the Horcrux, adding another layer of tragic heroism to the Black family history.
