Harry, Ron, and Hermione retrieve and destroy the Lost Diadem of Ravenclaw as Voldemort’s forces lay siege to the Hogwart’s castle. The castle enchantments cast by the dutiful Hogwarts staff hold off Voldemort’s army of Death Eaters, Snatchers, giant trolls, and other assorted evil riff raff (as expected, all clad in black) for a while, but the inevitable becomes a reality as the
sanctity of Hogwarts is eventually defiled with dark forces hungry for blood. There are some touching scenes throughout this portion of the film, as we see Hogwarts professors like the stern yet grandmotherly McGonagall, defend not only the castle, but the children she has nurtured and educated for so many years.
Harry discovers through his mental connection to Voldemort, that the snake Nagini is the last horcrux. Harry, Ron, and Hermione track down Voldemort and Nagini in the Hogwarts boathouse, where the Dark Lord has summoned Snape for a discussion. In a subplot involving the allegiance of the Elder Wand, Voldemort commands Nagini to attack and kill Snape so that the Elder Wand will answer to him alone. Voldemort dissapparates, leaving Snape mortally wounded, but alive. Once again, Harry displays his endless compassion and humanity as he tends to Snape’s wounds. Snape asks Harry to gather his tears, which contain vital memories, and bring them to one of the greatest plot exposition contrivances ever, the Pensieve.
Harry and the Hogwarts faithful are granted a temporary cease fire by Voldemort, who demands that Harry meet him in the Forbidden Forest within an hour, or have the blood of every man, woman, and child who conceals him on his hands. Harry honors Snape’s dying wish and uses the Pensieve to view his memories. In what could only be described as an emotional roller coaster flashback sequence, we learn what I suspected all along, that Snape was in fact loyal to Dumbledore and Harry since the first film. The memories reveal Snape’s lifelong love for Harry’s mother Lily and the obsessive allegiance he pays to her, by protecting Harry throughout his entire life. So much is revealed in that sequence and its impact to the storyline, the characters, and the plot are enormous. Recounting it here does not do it justice.
Harry returns to the Forbidden Forest, where he pretends to be dead following his Avada Kedavra ride of the green lightning. Narcissa Black inspects Harry’s body for Voldemort and finds that he is alive. Much like Draco did not reveal Harry’s identity to Bellatrix LeStrange when he had the opportunity at the end of Deathly Hallows Part 1, Narcissa lies to the Dark Lord and claims that Harry is dead, in the hope that she can be re-united with her son Draco, whom Harry has revealed is still alive at Hogwarts.