Batman Gotham Knights #5 2000

In Batman: Gotham Knights #5, The Key unleashes chaos at Arkham Asylum, starving inmates and injecting Batman with a serum that amplifies his rage. Batgirl and Azrael must intervene to prevent Batman from succumbing to his primal instincts and killing The Key. Robin also falls victim to The Key's machinations. This issue is notable for its intense psychological exploration of Batman's inner demons and features key members of the Bat-Family confronting a cunning adversary within the iconic Arkham Asylum setting.