Harry Potter and the Dealthy Hallows is the seventh and final book in J.K. Rowlings Harry Potter series. Voldemort is continuing to accumulate power and it is up to Harry, Ron, and Hermoine to find the remaining Horcruxes to defeat him once and for all. When the Death Eaters descend upon Hogwarts, it leads to a battle that will affect the future of the wizarding world forever.
They stun the Carrows and begin to tell Professor McGonagall what they’re up to. They tell her that they must find the lost diadem before Voldemort gets into the castle. McGonagall tells Harry that she and the others will secure the castle against Voldemort as long as they can so that Harry can search for the diadem.
As they’re walking through the hall they run into Snape. He and Professor McGonagall duel fiercely with magic so quick that Harry has never seen the like of it. When the other professors show up to help McGonagall, Snape jumps out one of the windows to join Voldemort, who is now just outside the grounds.
The professors immediately begin putting charms and spells all around the castle to hold off Voldemort.
When Harry gets back to the Room of Requirement he’s shocked to see that even more people have shown up, including Lupin, Kingsley, and Ron’s whole family. Finally, even Percy shows up and apologizes to his family, saying that he was a deluded idiot and that he’s sorry he’s been such a big prat for so long. His family forgives him instantly, and they all leave to join the battle together.