Following Dumbledore’s death, Harry is moved to a safe location and during this event Mad-Eye is killed. Ron and Hermione decide to join Harry in his quest to destroy the Horcruxes.
Some of the clues that Dumbledore left them included: a Golden Snitch for Harry, a Deluminator for Ron, and a book of fairy tales for Hermione.
During Bill Weasley’s wedding, the Ministry of Magic falls. Harry, Ron and Hermione flee to 12 Grimmauld Place in London. They identify R.A.B. as Sirius’ brother Regulus Black and Kreacher reveals that he stole the locket and it now belongs to Dolores Umbridge. They manage to retrieve the locket but cannot destroy it. Ron becomes increasingly angry especially due to the locket’s influence and leaves the trio.
Harry and Hermione travel to Godric’s Hollow, Harry’s birthplace where they meet historian Bathilda Bagshot, but she turns out to be Nagini in disguise. They escape to Forest of Dean. A Patronus appears to Harry and guides him to an icy pond containing the Sword of Gryffindor. However, the locket around his neck tries to kill him through the Horcrux and Ron saves Harry. Ron uses the sword to destroy the Horcrux.
They visit Xenophilius Lovegood and he explains to them about the Deathly Hallows. Harry realises that Voldemort is seeking the Elder Wand. However, they are all captured and taken to Malfoy Manor. They escape and Griphook tells them of Helga Hufflepuff’s cup, which is another Horcrux. They break into the vault, retrieve the cup, and escape on a dragon. They enter Hogwarts through a passageway. Harry realises that Rowena Ravenclaw’s diadem is a Horcrux. Ron and Hermione destroy it with a basilisk fang.
Voldemort kills Snape after assuming that the Elder Wand is not working because it’s loyalty lies with Snape, who disarmed Dumbledore. Snape passes Harry his memories to view in a Pensieve. It is revealed that Snape was a double agent working for Dumbledore because he loved Lily Potter. It was Snape’s doe Patronus that lead Harry to the sword.
Neville Longbottom manages to kill Voldemort’s snake Nagini, the last Horcrux. Voldemort uses the killing curse against Harry. Harry enters Limbo where he meets Dumbledore who explains to him that Voldemort has killed the link between himself and Harry. Harry returns to the living world. Voldemort and Harry battle. Harry reveals to Voldemort that the Elder Wand cannot harm him because its loyalty lies with Harry, as he was the one to disarm Draco Malfoy, who disarmed Dumbledore.
Voldemort cast the killing curse on Harry but it refutes and he ends up killing himself. Harry destroys the Elder Wand after the war and the wizarding world returns to peace once more.
In the epilogue, 19 years later, Harry, Ron, Hermione see off their children who are off to Hogwarts.