The Calculus Affair: Part 2 - S1-E13
Audio problem: When Tintin, Haddock and Calculus exit the hospital, Haddock says "Blistering barnacles, I'm glad to be out of there. The food was terrible". His mouth doesn't move when he says "The food was terrible". (00:25:50)
Answer: According to Wikipedia, he is described as being a youth anywhere from 14 - 19 years old. There is no specific age.
raywest ★