“I was interested in this role because he goes on this journey from dying to finding a cure for this disease and becoming incredibly healthy, and then having things change in a way that he becomes monstrous,” Leto said. “You start with a hope and a dream and an idea of something, and you all try to work as hard as you can, in this given amount of time, to make it as good as it can be. And I think it’s the first time I’ve ever starred in a big movie like this in my entire career, so it was new territory. I generally hide out in the shadows.”