Craig Gillespie knew that he had to direct Supergirl as soon as he started reading the script.

The 58-year-old filmmaker is behind the camera on the new DC Universe (DCU) blockbuster - which stars Milly Alcock in the title role - and explained how reading just two scenes of Ana Noguiera's screenplay convinced him to take on the project.

Gillespie told The Playlist: "I got sent the script kind of out of the blue. I wasn't necessarily looking to do a large tentpole superhero film, but I've always loved James (Gunn's) work. And I thought, if there's any sensibility that I relate to, it's James'.

"I got this script, still with reservations, but then I read it. Literally, second scene in, I'm like, 'All right, I'm in. I know this movie. I know how to do this.'"

The Cruella director continued: "Between that very intense opening scene and then the bar scene with Milly, and the pathos and the humour and just the abruptness of it and the irreverence of it, I was so excited about the tone of this. And Ana did an amazing job.

"So then I went in and pitched myself to James and Peter (Safran). They were meeting several directors, but it was critical to me to pitch my version of the film. I wasn't trying to second-guess what they were doing.

"So I came in and showed 120 images of what I thought this movie should be. And I also pitched that I don't think we should see her in the superhero outfit until as late as possible in the movie because of the emotional journey she's on, and when she's ready to actually wear it. And they amazingly embraced it all."

Alcock had already been cast as Supergirl before Gillespie joined the project and the filmmaker said he was "fortunate" to get the chance to work with the Australian actress.

He said: "I did inherit her, very, very fortunately. Amazingly, the lead actor is probably the most contested, discussed, and controversial piece of filmmaking. And it's a very unusual thing that I get to come into this, and it's already been decided.

"But in so many ways, it set the tone for the whole film because I love Milly's work that I'd seen in House of the Dragon and in her work in Australia.

"Knowing that that's what they wanted this movie to be, because in her work in the past, there's scrappiness, or fierceness, or a humour and accessibility in all of her work. And there's almost this independent spirit that I loved.

"So being able to know that's what James was recognising as Supergirl, it gave me more licence to really lean into that. I couldn't have been more excited about Milly being attached beforehand."