When does Sleeper Cell return?

Sleeper Cell is an American one-hour drama on the Showtime network that began airing on December 4, 2005. Darwyn Al-Sayeed, a 30-year-old American undercover FBI agent, is assigned to infiltrate a terrorist sleeper cell that is planning an attack in Los Angeles. The writers offer a non-stereotypical mix of cell members, including a white European woman, a Latino-American man and, in a first for American television, a gay Muslim man.