Harry Potter and the Deathly Hallows by J. K Rowling

In the final installment of this popular series, the protagonist and his friends decide to leave their school to complete the mission left to them by their late headmaster - to destroy the remaining pieces of the antagonist's soul, hidden in various objects. As they journey through the wizarding world, they uncover the truth about the antagonist's past and the legend of the Deathly Hallows. Amidst the escalating war, they are captured and narrowly escape, leading to the ultimate battle at their school where many lives are lost. The protagonist learns he must sacrifice himself to truly defeat the antagonist, but is given a second chance at life and finally triumphs, ending the war. The story concludes with a glimpse into the peaceful future they have all earned.

The 816th greatest book of all time