The Minister of Magic Rufus Scrimgeour addresses the wizarding media, stating that the Ministry remains strong despite Lord Voldemort gaining power and the Death Eaters committing mass killings of Muggles and infiltrating the Ministry. Meanwhile, Harry Potter, Ron Weasley, and Hermione Granger resolve to complete the mission Albus Dumbledore gave Harry by hunting down and destroying Voldemort’s Horcruxes. Severus Snape informs Voldemort of Harry’s impending departure from Privet Drive. Voldemort commandeers Lucius Malfoy’s wand, due to his own wand sharing the same core as Harry’s and therefore being unable to kill him.
The Order of the Phoenix escort Harry to safety using Polyjuice Potion. During their flight, they are ambushed by Death Eaters who kill Mad-Eye Moody and Hedwig, injure George Weasley, and incapacitate Rubeus Hagrid. Arriving at The Burrow, Harry has a vision of the wand-maker Gregorovitch being tortured by Voldemort. The next day, Scrimgeour arrives with Dumbledore’s will. Ron receives Dumbledore’s Deluminator, Hermione receives a copy of The Tales of Beedle the Bard, and Harry receives the first Golden Snitch that he caught in a Quidditch match. Scrimgeour reveals that Harry was also bequeathed the Sword of Gryffindor, which has gone missing.
The Death Eaters kill Scrimgeour and replace him with Pius Thicknesse. The Ministry begins arresting and persecuting Muggle-born witches and wizards. Death Eaters also attack during Bill Weasley and Fleur Delacour’s wedding. Kingsley Shacklebolt’s patronus charm forewarns the wedding party, and most escape. Harry, Hermione, and Ron disapparate to London, but are attacked in a diner by Death Eaters. The trio seek refuge at Number 12, Grimmauld Place. They discover that the “R.A.B.” from the fake Horcrux locket is Regulus Arcturus Black, younger brother of Sirius Black. Kreacher, the Blacks’ house elf, tells them that Mundungus Fletcher broke in and stole many items from the house, including the real locket. Kreacher and Dobby apprehend Fletcher, who reveals that the locket is in the possession of Dolores Umbridge. Using Polyjuice Potion, the trio infiltrate the Ministry and find the locket around Umbridge’s neck. Harry stuns Umbridge and Hermione retrieves the locket. The trio escape their pursuers by apparating in the wilderness, but Ron is injured and cannot apparate again until he recovers.
After unsuccessful attempts to destroy the Horcrux, the trio take turns wearing it to dilute its power. Harry sees a vision of Voldemort interrogating and killing the wand-maker Gregorovitch, who claims a teenage boy stole the legendary Elder Wand from his shop. While Ron is wearing the locket, he is overcome by negative feelings and falls out with Harry before abandoning him and Hermione. Hermione deduces that the Sword of Gryffindor can destroy Horcruxes and decides to go with Harry to Godric’s Hollow. They visit Harry’s parents’ graves and the house where they were killed. They encounter Bathilda Bagshot, who they believe may have the sword. Bathilda lets them into her house before revealing herself as Nagini, possessing Bathilda’s reanimated corpse. Hermione and Harry escape into the Forest of Dean, but Hermione accidentally breaks Harry’s wand whilst fighting Nagini. She identifies the mysterious thief in Harry’s vision as Gellert Grindelwald.
Harry sees a Patronus in the form of a doe, which leads him to a frozen pond. Gryffindor’s sword lies beneath the pond’s ice, which Harry breaks and jumps into. The locket around his neck strangles Harry, but Ron arrives and rescues him. Harry uses parseltongue to open the Horcrux locket, which Ron eventually decides to destroy. Hermione and Ron reconcile, and the trio decide to visit Xenophilius Lovegood to learn more about a symbol left in the book Dumbledore left Hermione. Lovegood explains to them that the symbol represents the Deathly Hallows, three magical objects that can make a wizard master of Death. Hermione reads the story of the Hallows, after which the trio awkwardly attempt to leave but are stopped by Lovegood. He reveals that Luna Lovegood has been kidnapped and then summons the Death Eaters, intending to hand over Harry in exchange for her. Harry, Ron, and Hermione disapparate as Lovegood’s house is destroyed.
Back in the wilderness, the trio set up camp when Snatchers find them. Hermione uses a curse to disguise Harry as the Snatchers take them to Malfoy Manor. Bellatrix Lestrange imprisons Harry and Ron in the cellar with Luna, Ollivander, and Griphook the goblin. Bellatrix tortures Hermione for information on the Sword, which Bellatrix claims was in her vault at Gringott’s. Harry requests help, communicating with a broken mirror in his possession. Dobby apparates into the cellar to save them. Harry and Ron rush to save Hermione, and a battle ensues that sees Harry disarm Draco Malfoy. Dobby drops a chandelier onto Bellatrix, forcing her to release Hermione. Bellatrix throws her knife at them as Dobby grabs everyone and disapparates. They arrive at Shell Cottage to find that Bellatrix’s knife has fatally wounded Dobby. Harry insists that they bury Dobby without any magic. Meanwhile, Voldemort breaks into Dumbledore’s tomb and steals the Elder Wand, revealed to have been in Dumbledore’s possession.