Absolute Batman by Alan Moore

The Killing Joke

An infamous criminal mastermind aims to prove that one bad day can push anyone over the edge, crippling a young vigilante and subjecting a steadfast police commissioner to psychological torture. As a brooding detective closes in, fragmented flashbacks hint at a tragic past that blurs the line between hero and villain. The tale confronts trauma, moral ambiguity, and the unsettling, cyclical bond between two sworn enemies.

Purchase from Bookshop.org