After a four-year hiatus, "Black Mirror" is finally back! Season six is now streaming on Netflix, and we're taking a look behind three of this season's five episodes: "Joan Is Awful," "Beyond the Sea" and "Mazey Day" with their respective stars Salma Hayek Pinault, Annie Murphy, Josh Hartnett, Kate Mara, Zazie Beetz, Danny Ramierz and Clara Rugaard.