Starz has unveiled the trailer and key art for “Gaslit,” its limited series that tackles the Watergate scandal. The show focuses on the perspective of Martha Mitchell (Julia Roberts), the wife of Richard Nixon’s attorney general, John Mitchell (Sean Penn). “Gaslit” will debut on Starz’s digital platform at midnight on April 24, with a linear debut the same day at 8 p.m. Et.

Roberts is on fire in the trailer, Arkansas accent and all, as a political storm swirls around her, and Penn is nearly unrecognizable in his prosthetics and hair pieces. At one point, John slaps Martha across the face, to which she responds by slapping him back, adding, “My momma slapped me harder than that.”

Martha was the first person to publicly blow the whistle on Nixon’s involvement in the infamous scandal, which kicked off an avalanche of political and personal consequences. John was Nixon’s close advisor and friend,...