Irrfan Khan and Sidse Babett Knudsen also on for Ron Howard's latestWith Tom Hanks back as Dr. Robert Langdon and Felicity Jones now confirmed as his co-star, Ron Howard is boosting the cast of his latest Dan Brown adaptation, Inferno, by three. Omar Sy, Irrfan Khan and Sidse Babett Knudsen have all made deals to appear in the thriller.Inferno finds Hanks’ symbologist in Italy, grappling with amnesia and a chilling puzzle revolving around Dante’s Inferno.