Natalie Portman knows "fair is foul and foul is fair," and she is now totally ready to give those celebrated acting chops a real Shakespearean stretch next.

Per Screen Daily, the Oscar-winning "Black Swan" star has just signed on to star in the Justin Kurzel-led adaptation of "Macbeth,"  the script for which has been super buzzy with Cannes Film Festival sales crowd.

Also, it appears no love was lost between herself and her "Untitled Terrence Malick Project" co-star Michael Fassbender after he dipped out on her "Jane Got a Gun" production — his exit was the first of several for the troubled western — because he'll star as her leading man in the pic, the titular brute Scottish lord whose wife (Portman's role, naturally) and three witches helped get him onto the throne.

"Double, double toil and trouble; Fire burn, and cauldron bubble." We could do this quoting thing all day, especially since the screenplay uses original dialect.

Reportedly, Portman's been mulling her options with the story of "Macbeth" for a while, even considering a stage variation or two, but Fassbender's involvement sweetened the cauldron on this one.

He'd been previously attached to sling some pistols with her out in New Mexico but ditched the rootin' tootin' movie just before shooting commenced. "What's done is done," as the master playwright himself once said.

The last time Portman was seen in a period piece, if you wanna even call it that, was with the 2011 flop "Your Highness" ... which shoudla just been retitled "Your Hiney" because that's pretty much all anyone remembers of her in the film.

Shooting for "Macbeth" is expected to commence later this year.