WARNING: The following contains spoilers from Batman #122, on sale now from DC Comics.
Batman #122 showcases an early battle between the Dark Knight and Deathstroke, who reveals on the issue's final page that he's received a dose of what appears to be Joker Venom.
The confrontation plays out in "Secret Meetings," the issue's backup story written by Joshua Williamson and illustrated by Trevor Hairsine. Taking place early in Batman's career, the tale opens up with Commissioner Gordon revealing that an unknown assailant has put a hit out on Robin. The hitman delivering the assassination is none other than Deathstroke, who attempts to snipe Dick Grayson from a rooftop before Batman stops him with a Batarang.
Batman and Deathstroke trade blows in a retconned version of their very first meeting, with Slade Wilson admiring Batman's fighting style and identifying several martial masters the pair are both familiar with, including Henri Ducard and Ted Grant (also known as Wildcat). When Batman demands to know who hired him, Deathstroke can only answer that his employer had lots of money, paid in advance, and spoke in a creepy voice over the phone. Finally, Slade removes his mask to reveal a rictus grin -- a clear sign of Joker's trademark toxin.
Joker Venom was first used by the Clown Prince of Crime in his very first appearance in 1940's Batman #1 and has become a fixture of the character ever since. Most recently, Joker Venom was used to kill a huge number of Arkham Asylum inmates in 2021's Infinite Frontier #0. The cataclysmic attack -- dubbed "A-Day" by Gotham City's media -- resulted in the death of Bane.
Joker Venom also featured in the origin of the fan-favorite Batman Who Laughs, an alternate universe Batman who killed the Joker in a rage only to be sprayed with the chemical compound in the dying clown's final moments. The toxin slowly transformed Bruce into a horrific amalgamation of Batman and the Joker who went on a killing spree across his version of the DC universe.
How Batman goes on to treat Deathstroke remains to be seen, but Slade seems unlikely to let Joker get away with manipulating him. The master assassin was framed for killing Ra's al Ghul in "Shadow War," the ongoing crossover between Batman, Deathstroke Inc. and Robin that kicked off last month with the one-shot Shadow War: Alpha #1.
Batman #122 is on sale now.