Actress Dafne Keen says her "His Dark Materials" co-star Lin-Manuel Miranda is always singing.

"Yes, he does sing, but I also sing so we were always singing together," Keen said when asked if Miranda is always singing.

"Every time Lin turned around and we were in the air balloon, me and Lewin (Lloyd) would sing Hamilton because we were too embarrassed to sing it to his face. I love Ruth (Ruth Wilson) too, she is brilliant. Doing scenes with her is so fun. She is very psychopathic and then she is really nice in real life," she added.

In "His Dark Materials", which will air in India on Star World, brings to life Philip Pullman's world of witches, armoured bears and daemons. It stars Keen as Lyra Belacqua, Wilson as the icy Mrs. Coulter, James McAvoy as the aloof Lord Asriel, and Miranda as the adventurous balloonist Lee Scoresby.

Talking about the role, Keen added: "It most certainly was nerve-wracking. I was like, 'Oh my God, so many people have read the books and love Lyra'. Every time I go somewhere and people know I'm playing Lyra they are like, 'She is the role model of my childhood'. It's very nerve-wracking thinking you've got to live up to everyone's expectation of being their role model."

What would you say 'His Dark Materials' is about?

"It is about growing up I think. It's about growing up because even though it's decorated with fantasy and stuff, it's really the story of a child turning into a woman. In book one, there's this whole thing of the system trying to rip us of our souls and our personality, which is what daemons represent. The whole thing is not necessarily a criticism of the system, but it is asking questions," the actress said.