EXCLUSIVE: Tuc Watkins (Desperate Housewives) is set for a season-long guest-star arc on Season 2 of Black Monday, Showtime’s 1980s Wall Street comedy starring and executive produced by Don Cheadle.

Erin Simkin/SHOWTIME

Written by David Caspe and Jordan Cahan, the series takes viewers back to October 19, 1987, aka Black Monday. No one knows who “caused it” — until now. It’s the fictional story of how a group of outsiders took on the blueblood, old-boys club of Wall Street and ended up crashing the world’s largest financial system, a Lamborghini limousine, and the glass ceiling. Andrew Rannells, Regina Hall and Paul Scheer also star.

Watkins will play Congressman Harris, a Republican and leader of the Moral Majority.

It’s a return to Showtime for Watkins, who played Malcolm Laffley on Beggars and Choosers. He also starred or recurred on such TV series as Desperate Housewives, Major Crimes, Awkward, Parks and Recreation, Sisters, C16: FBI and One Life to Live. Repped by Artists & Representatives and Karen Forman Management, his recent guest-star work includes Ballers, Castle, It’s Always Sunny in Philadelphia and Maron.

Black Monday is created by executive producer/showrunner David Caspe (Happy Endings), and Jordan Cahan (My Best Friend’s Girl). Seth Rogen and Evan Goldberg also are EPs. The 10-episode sophomore season of the series — a co-production of Showtime and Sony Pictures TV Studios — will premiere next year on the premium cabler.