Peter Krause will also star in the series. Margulies will play Jennifer, a mysterious woman who goes to Detective Joe Miller, Krause, after her brother is killed over what seems to be a normal motel room key, said the Hollywood reporter Tuesday.
The key ends up actually having the ability to unlock a door into a room full of unimaginable power.
Roger Bart has also been cast in the Lionsgate-produced series, which is set to premiere in December.
The project is in production in Albuquerque.