Jonathan Groff and Sanaa Lathan Sign on for Second Season of BOSS

According to Deadline.com, theatre veterans Jonathan Groff and Sanaa Lathan will guest star on the upcoming second season of Starz's 'Boss.' Lathan will play 'Mona, Kane's incorruptible new chief of staff, who becomes an obsession for him,' and Groff 'Ian Todd, a smart and ambitious  staffer in Kane's office who steps into the void Ezra Stone (Martin Donovan) has left to offer astute council to Kane.'

BOSS is the story of Mayor Tom Kane (Kelsey Grammer) who sits like a spider at the center of Chicago's web of power; a web built on a covenant with the people. They want to be led, they want disputes settled, jobs dispensed, and loyalties rewarded. If he achieves through deception and troubling morality, so be it. As long as he gets the job done, they look the other way.

Yet despite being the most effective mayor in recent history, a degenerative brain disorder is ripping everything away from him. He can't trust his memory, his closest allies, or even himself.

Kane's wife Meredith (Connie Nielsen) knows nothing. Theirs is a marriage of convenience. Kitty O'Neil (Kathleen Robertson), Kane's advisor, has her suspicions but stays silent. And Kane's political advisor Ezra Stone (Martin Donovan), a Yale graduate with a rough edge, remains questionless.