There’s some bad familial blood between Margot Robbie and Saoirse Ronan in their newest film.

Robbie and Ronan — who were both nominated for Best Actress at this year’s Oscars — are at odds in  Mary Queen of Scots, a period piece centered of the lives of Queen Mary of Scotland and Queen Elizabeth I in the mid-1500s.

Ronan stars as Mary, who has just come back to Scotland to reclaim her throne after the death of her husband, King Frances II. Her presence brings tension to her cousin Elizabeth (played by Robbie), who sits on the English throne.

Though the cousins briefly agree to live in harmony, the trailer shows how their relationship becomes more complicated as the men around them scheme for power.

“Everyone manipulated their relationship,” Robbie told EW of Mary and Elizabeth. “It’s complicated, it’s tragic, and it’s bizarre. The only other person in the world who could understand the position they were in was each other.”

The trailer also offers a look at the stunning period costumes and sets, and Robbie’s transformation into the Queen of England. The I, Tonya star is wearing layers of prosthetics and makeup to transform into Elizabeth, who was scarred from smallpox and often sported heavy white makeup to cover them.

It also offers a glimpse of Taylor Swift’s boyfriend Joe Alwyn as Robert Dudley, a suitor and close friend of Robbie’s Queen Elizabeth.

Mary Queen of Scots hits theaters Dec. 7.