Netflix's new No. 1, Black Doves, is a British action spy thriller that has already lined up a second season.Keira Knightley stars in the series as Helen Webb, a woman on a mission of revenge.Black Doves takes place during the Christmas season.Along with Knightley, the show stars Ben Whishaw as Sam Young, one of the most efficient killers in the Black Doves.The show predominantly concentrates on its two stars, Knightley and Whishaw.Knightley is the primary character, who after the murder of her lover, is left to hunt down his killer.Black Doves tells a complete story in only six episodes, making it a very satisfying watch.The series has a deep bond between Helen and Sam, despite spending years apart, giving it its heart.The show's hints about where it can go in its second season leaves fans eager for more of Helen and Sam in this world.Black Doves is a great Christmas present for Netflix viewers who needed some excitement.