The riveting trailer shows Stewart channeling the late Princess of Wales as the royal family gathers for Christmas. A tense confrontation with Prince Charles (played by Jack Farthing) takes place in a plush Sandringham estate drawing room, with a billiards table between the two.
Charles can barely contain his anger toward Diana because people are talking about how she's late.
Kristen Stewart says Princess Diana movie isn't a biopic: It’s about ‘how she makes us feel’
"You have to be able to do things you hate,” Charles says. "That you hate?" Diana replies, with Stewart nailing the tone and accent.
"There has to be two of you," Charles tells her. "The real one and the one they take pictures of ... For the good of the country."
Prince William asks why she's so sad. “Here in this house, there is no future," she tells her sons. "The past and the present are the same thing.”
Later, she says, "There’s no hope for me, not with them” and wonders "Will they kill me, you think?
An earlier teaser trailer opened with images of Christmas dinner being prepared and shows flashes of different scenes from the movie.
"Ma'am, they're waiting for you," a person off camera says to the princess after knocking on her door.
We later see an exchange between Princess Diana and a friend in the garden.
"They know everything," the friend says. "They don't," replies the princess.
Stewart was already expected to be in the Oscar best actress conversation for the showcase, but expectations have shot up after the film's rapturous reception at Venice International Film Festival and Toronto International Film Festival.
Shortly after the teaser trailer dropped, Princess Diana became a trending topic on Twitter with folks in awe over Stewart as the late royal.
"Kristen Stewart is a living legend portraying Princess Diana," tweeted @everydayrobsten.
@alisalem147 wrote: "Kristen Stewart as Princess Diana...I really have a good feeling about this and I think Kristen will get an Oscar nomination."
Film critic Scott Menzel, who saw extended footage of the film in August at CinemaCon, the national convention of theater owners, was one of many attendees wowed by Stewart's performance.
"Based on the footage, it looks like Kristen Stewart will be getting an Oscar nomination for her performance as Diana," Menzel tweeted. "I’m feeling very confident that this is going to be #KristenStewart’s big moment."
I just saw the teaser trailer for #Spencer & a 5 minute clip from the film. Based on the footage, it looks like Kristen Stewart will be getting an Oscar nomination for her performance as Diana. I’m feeling very confident that this is going to be #KristenStewart’s big moment. pic.twitter.com/TeOfP3gXm1
— Scott Menzel (@ScottDMenzel) August 25, 2021
Entertainment Weekly critic Lauren Huff wrote on Twitter: "Let me just say: WOW. Cannot wait to see the rest. Kristen Stewart nails it" before adding, "I sense an Oscar nod in her future."
Insider entertainment correspondent Jason Guerrasio wrote on Twitter, "Kristen Stewart is going all out for that Oscar glory. And her Princess Di accent is spot on!"
"Spencer" stars Sally Hawkins as Diana's confidante and Timothy Spall as a security member sent by Queen Elizabeth II to keep the paparazzi at bay and Diana on a short leash.
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This article originally appeared on USA TODAY: 'Spencer' trailer: Kristen Stewart's Princess Diana confronts Charles