The Nightwing movie remains one of the best-kept secrets on the DC slate. We know it's coming, but few other details related to Chris McKay's upcoming project have been revealed since its initial announcement. However, McKay recently opened up to CinemaBlend and admitted that the film will definitely refer to Dick Grayson's years as a circus performer. During a discussion about his work on The LEGO Ninjago Movie, I asked The LEGO Batman Movie director if Haly's Circus would make an appearance in the upcoming Nightwing movie, McKay said:
Yes. In some form. There will be lots of nods. Lots of nods.
For all of the Nightwing newcomers out there, Haly's Circus is relevant to his origin story because Dick Grayson was a child acrobat (and a member of the Flying Graysons ensemble) before the death of his parents in a trapeze accident. Their death during a show in Gotham forces his retirement from his life as a performer, which eventually sees him taken under Bruce Wayne's wing as his ward -- and his eventual birth as Robin. The fact that Haly's Circus will play a role in the Nightwing story means that we won't simply catch up with him as an adult superhero who has moved on from his time in Batman's shadow. The story will (at least partially) focus on his origins, as well as how he actually became a world class acrobat.
This wouldn't be the first time that Haly's Circus has appeared in a DC film. The talented (yet doomed) Flying Graysons made an appearance in Joel Schumacher's 1995 film Batman Forever, and changed Robin's origin story to make him a young adult at the time of his parents' death -- which was retconned to be the result of Two-Face's actions, instead of mobster Tony Zucco.
As excited as we are about this development, it's worth remembering that a "nod" can mean quite a few different things; the nature and purpose of Haly's Circus have changed considerably over the years. Sometimes Dick Grayson has returned to it because of an investigation (a la Young Justice), while in other instances he has actually purchased the operation and become the man behind the show. In Batman: The Court of Owls, it was even revealed that the circus once served as a proving ground for The Court's deadly Talon assassins -- something Dick Grayson would've eventually become if Bruce Wayne had never adopted him.
With so many different avenues for storytelling, it's almost impossible to tell where these "nods" will take Dick, but the confirmation of Haly's Circus in Nightwing's story certainly bodes well for its fidelity to the source material. Like the inclusion of Krypton in Man of Steel or the inclusion of Themyscira in Wonder Woman, it's fundamental to establishing the nature of our hero.