- Evolution's a funny thing... No matter how many obstacles get in its way, the strongest always survives. Still, you know what they say about evolution? Even amoebas can do it.
- — Henry Adams src
Over a year ago, the supervillain known as the Joker staged a rebellion at Arkham Asylum, forcing Batman to single-handedly regain control of the prison from the lunatics. As Joker's plan began to go sour, the criminal made a final move to defeat Batman by injecting himself with a derivative of Bane's strength enhancing drug Venom that he had been experimenting with called Titan. Gaining temporary super strength, Joker was again defeated by Batman and returned to cell in Arkham. 
NA few months later and nine months ago, during Batman's takedown of the recently created super prison Arkham City, the Joker, having developed a mysterious terminal illness from his exposure to the Titan formula, shipped his blood all around Gotham and even infected Batman himself with it as a way of forcing the Dark Knight to discover a cure. Batman delivered and discovered a cure for the Joker's illness, only for the clown to accidentally seal his own fate by destroying the cure in his final fight with the Bat. The Joker, therefore, succumbed to his illness and died, but his tainted blood managed to make it to several hospitals around Gotham. 
Henry Adams was one of the five people infected with the Joker's blood who didn't get treated in time, which caused the blood to gestate too long and begin to turn the victims into the Joker. Adams, the longest exposed, had shown no symptoms and had actually worked with Batman to try to cure himself.
On Halloween, Scarecrow had seized control of Gotham and encouraged Batman's rogues to get their final shots in on the Dark Knight. During this time, Adams had finally shown just how insane he had become when Harley Quinn invaded Batman's top secret containment facility. Henry, smearing blood across his face to resemble a Glasgow smile, killed the other infected people, claiming that there could only be one Joker. Realizing that Batman, too, was infected by the Joker's blood and was losing his sanity as well, admitted that the Dark Knight would be the perfect Joker and shot himself. 
- Pedagogy: Adams was the principal of a private school in Gotham before being infected by the Joker's tainted blood.
- Mental Illness: Although completely sane before being infected, Adams slowly went insane after being exposed to the Joker's blood.
- 1 Appearances of Henry Adams (Arkhamverse)
- 1 Images featuring Henry Adams (Arkhamverse)
- 1 Quotations by or about Henry Adams (Arkhamverse)
- Character Gallery: Henry Adams (Arkhamverse)