As Todd Phillips' Joker origin film begins principal photography, the script for the Joker & Harley Quinn spinoff film set within the DCEU is now complete.

Filmmakers Glenn Ficarra and John Requa have confirmed they have turned in a draft for the planned DC adaptation focused on the titular villainous couple while observing that the story takes inspiration from their previous work on the black comedy Bad Santa and television series This Is Us.

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"The whole thing starts with Harley kidnapping Dr Phil. Played by Dr Phil hopefully. Because her and the Joker are having problems with their relationship," explained Ficarra in an interview with Metro. "We wrote Bad Santa a couple of years ago, and it was that sensibility mixed with our This Is Us sensibility. We kind of meshed them together."

The duo are also attached to the Warner Bros. project as directors, having previously directed the first six episodes of This Is Us as well as directing Harley Quinn actor Margot Robbie in 2015's Focus and 2016's Whiskey Tango Foxtrot.

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"We handed the script in and everybody loved it," continued Ficarra. "But I don’t know when they are going to do it."

In the meantime, Robbie is next expected to reprise her role as Harley in the DCEU's Birds of Prey which is expected to start principal photography this January.