Captain Haddock the Picaros", when Professor Calculus 'cures' him of his taste for alcohol. In the adventure "Secret of the Unicorn" (and continuing in "Red Rackham's Treasure") he and Tintin travel to find a pirate's treasure captured by his ancestor, Sir Francis Haddock (François de Hadoque in French). With newfound wealth and regaining his ancestral home Marlinspike Hall, Captain Haddock becomes a socialite; riding a horse, wearing a monocle, and sitting in a theatre box seat ("The Seven Crystal Balls"). He then evolves to become genuinely heroic, volunteering to sacrifice his life to save Tintin's own in the pivotal "Tintin in Tibet".
Tintin in Tibet trace Chang's steps, and finds a cave where Chang has carved his name on a rock. On leaving the cave, he encounters a snowstorm and glimpses what seems to be a human silhouette. Tharkey believes that Tintin saw the Yeti and convinces him to abandon his friend and return with him to Nepal, since the area is too large to search. Tintin spots a scarf on a cliff face, concludes Chang is nearby, and continues with only the Captain. While attempting to scale a cliff face, Haddock slips and hangs out of reach, imperilling Tintin, who is tied to him.