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.
Neville is overjoyed to see them but Harry is horrified at Neville, who looks like he recently got beat almost to death. Neville leads them through the portrait down a long, dark hallway. It’s the last secret passageway into Hogwarts. As they walk, Neville fills them in on what’s been happening at Hogwarts. It’s been horrible, and the three can’t believe at how different things are at the school.
When they get there they are surprised to come out in the Room of Requirement. There is a cheering crowd waiting for them, and they’re all happy to see their old friends again.
There’s an argument, however. Harry knows that they don’t have much time, but everyone wants to help him. He insists they stay behind, and he gets even more panicked when more and more people start pouring in from the Hog's Head. Luna, Dean, Fred, George, Ginny, Lee Jordan, and Cho Chang all come climbing through. Harry, with some urging from Ron and Hermione, agrees to let them help. He figures out that they’re looking for Ravenclaw’s diadem, a type of crown she wore.
When Luna takes Harry to the Ravenclaw common room to look at a picture of the lost diadem, they’re met by one of the Death Eater professors, Amycus Carrow, who instantly touches the Dark Mark to alert Voldemort that they found Harry.