Sissy Spacek Sissy Spacek

Big Love just got a whole lot bigger.

Oscar-winning actress Sissy Spacek is joining the HBO drama for a multi-episode arc as a powerful Washington, D.C., lobbyist, according to the L.A. Times.

Check out photos of Spacek through the years

The Emmy-nominated polygamy drama, whose fourth season is slated for early next year, has also cast Bella Thorne to replace Jolean Wejbe as Teenie, Barb and Bill's youngest daughter. Ben Koldyke has also signed on as Dale, a state-appointed trustee and love interest for Alby (Matt Ross).

Spacek has been nominated for Academy Awards six times, and she won for her portrayal of country legend Loretta Lynn in The Coal Miner's Daughter.