Margot Robbie's Harley Quinn will be the focus of a spin-off Christina Hodson writing Harley Quinn film Sebastian Stan joins I, Tonya
The project has been in the works for a while, spearheaded partly by Robbie, who became interested in Harley's backstory and the comics in general as she did her research to play Quinn in Squad.
While Christina Hodson had been writing the script, The Hollywood Reporter's update on the project has Geneva Robertson-Dworet now taking it over, and adapting Paul Dini and Guillem March's Sirens comic book, which featured characters such as Catwoman, Poison Ivy and others, with the main trio forming a team.
While there is a Suicide Squad follow-up and other potential spin-offs in development, the Quinn and co. film appears to be the one with the most traction. So Ayer will start developing it once he finishes up Bright for Netflix.