The series will focus on four suburban Chicago couples navigating the complexities of friendship and marriage
Sheen says it's time for his character to start "circling the drain"
The actress joins as a series regular, replacing Selma Blair
The former "Beverly Hills 90210" star will reprise his role as the boyfriend of Charlie Goodson's ex-wife
The FX star allegedly demanded Blair be fired because he believed she'd been bad-mouthing him
Selma Blair, Joshua Close, James D'Arcy and Rachel Miner star in the Canadian psychological thriller
Blair and Smith will play Sheen's therapist and ex-wife, respectively
The "Boardwalk Empire" star will make a guest appearance on Fred Armisen's upcoming HBO series