Actor Ron Donachie, best known for playing Ser Rodrik Cassel in 'Game of Thrones', will feature in R Madhavan's upcoming film 'Rocketry: The Nambi Effect'. Actress Phyllis Logan, who portrayed Mrs Hughes in British drama series 'Downton Abbey', will also be seen in the film. Thanking them for being part of his film, Madhavan shared a picture with the actors.