Gotham City
On December 13, 2016, Ayer was brought on board to direct the spin-off of "Suicide Squad", "Gotham City Sirens", which evolved into "Birds of Prey", starring Margot Robbie reprising her role of Harley Quinn. with director Cathy Yan. "Gotham City Sirens" remained in development, but as of April 2021, "Gotham City Sirens" has been put on pause.