An extended video preview has been released for Focus Features' Anna Karenina, director Joe Wright's adaptation of the classic Leo Tolstoy novel. Keira Knightley stars as the title character, who strikes up a love affair with the mysterious Count Vronsky (Aaron Johnson) to counter her dull marriage with Alexei Karenin (Jude Law). Check out this six-minute clip, featuring an audio introduction from Joe Wright.