The actress gave insight into how she’s preparing for the Pablo Larraín–directed film in a new cover story for InStyle. In the interview, Stewart revealed that even though production doesn’t begin until January, she’s already read multiple books on the late princess.
“In terms of research, I’ve gotten through two and a half biographies, and I’m finishing all the material before I actually go make the movie,” Stewart told the outlet. “It’s one of the saddest stories to exist ever, and I don’t want to just play Diana—I want to know her implicitly. I haven’t been this excited about playing a part, by the way, in so long.”
Stewart also revealed that she’s determined to perfect Diana’s sophisticated accent and has been working to fine-tune her pronunciation for the film.
“The accent is intimidating as all hell because people know that voice, and it’s so, so distinct and particular,” said Stewart. “I’m working on it now and already have my dialect coach.”
Spencer spans a pivotal weekend in the early ’90s, retelling Diana’s decision to end her marriage to Prince Charles and break away from the royal family. Back in June, Larraín expressed his delight over Stewart’s casting for the major role and shared his faith in her upcoming portrayal.
“The way she responded to the script and how she is approaching the character, it’s very beautiful to see,” said Larraín. “I think she’s going to do something stunning and intriguing at the same time. We’re very happy to have her, she’s very committed.”
This article originally appeared on Harper’s BAZAAR US.