According to reports Ewan McGregor filmed his scenes in 3 days.
Val Kilmer and David Mazouz both played the DC Comics superhero Batman / Bruce Wayne, in the film Batman Forever (1995) and the TV series Gotham (2014-2019), respectively. Additionally, Ewan McGregor portrayed the Batman villain Black Mask / Roman Sionis in the DC Extended Universe film Birds of Prey (2020). And William Fichtner played a small roll in The Dark Knight (2008) as one of the victims of the Joker.
This is the first film to feature Val Kilmer and Ewan McGregor together.
Second movie to feature Ewan and Clara McGregor since Christopher Robin; although they don't have any screen time together in this film.
Vincent Pastore and Lorraine Bracco both starred in The Sopranos (1999).