Actresses Emily Mortimer (who stars in "The Newsroom") and Dolly Wells ("Spy"), best friends in real life, play fictionalized version of themselves in the upcoming HBO comedy "Doll & Em," which the pair co-wrote with series director Azazel Jacobs ("Terri").

The six-part miniseries, which premiered at the London Film Festival, is a depiction of a friendship complicated by power struggles and insecurity, with Emily hiring Dolly, who's fresh off a breakup, to serve as her assistant while she shoots a movie in Los Angeles. John Cusack, Andy Garcia and Susan Sarandon are among the celebrity cameos, and the series premieres on March 19 at 10pm -- take a look at the new full-length trailer below.