Jack Lowden reveals his favorite bit of improv on 'Slow Horses': 'He doesn't know why he's doing it'

Jack Lowden reveals his favorite bit of improv on 'Slow Horses': 'He doesn't know why he's doing it.' He plays River Cartwright, who messes up during a training exercise, opposite Gary Oldman as the rude and obnoxious boss of Slough House. Gold Derby contributor Charles Bright hosts this webchat. SUBSCRIBE TO GOLD DERBY: https://www.youtube.com/user/goldderby CONNECT WITH GOLD DERBY Web: https://www.goldderby.com/ Facebook: https://www.facebook.com/GoldDerby/ X: https://twitter.com/GoldDerby Instagram: https://www.instagram.com/goldderby/ Newsletter: https://cloud.email.goldderby.com/signup/ ABOUT GOLD DERBY: Gold Derby features celebrity videos plus expert predictions, tracking who will win Oscars, Emmys, Grammys, Tonys, Golden Globes and top reality TV shows 'America's Got Talent,' 'American Idol,' 'Dancing with the Stars,' 'Survivor,' 'The Voice' and more.