It's easy to binge-watch all of Netflix's new mini-series Collateral, because there are just four episodes and no second season on the horizon. Carey Mulligan plays a detective hunting down a killer, subsequently unraveling a whole plot that touches on immigration, refugees, and mental health — and she does it all while pregnant . Both Mulligan and her character are expecting during the series (the actress gave birth to her second child with Marcus Mumford in September of last year), something that creator David Hare wrote into the script that ended up making an important statement.