Dunst, 42, and Plemons have shared screen space three times, including in Fargo, Power of the Dog, and Civil War.
The actor has fluctuated in weight for various roles, bulking up for his 2015 performance as mobster Kevin Weeks in Black Mass and carrying that build into his Fargo appearance before losing some.
In 2016, he reported to GQ: "I had lost a little bit of weight at the Fargo premiere, and I remember this guy asking, like, 'What's your secret to losing the weight?
The plot revolves around De Niro's character, former US President George Mullen, who steps back into the spotlight to serve his country once more as he probes a lethal cyberattack while grappling with personal issues.
The six-part limited series boasts an impressive cast including Jesse Plemons, Lizzy Caplan, Connie Britton, Joan Allen, Matthew Modine, and Angela Bassett.
