The Adventures of Tintin: The Secret of the Unicorn (video game) wants to get the third scroll, and that he is in fact Allan's boss. After a fight with Allan, Tintin gets the third scroll and heads off to Brittany, where he and Haddock earlier identified as Sir Francis' hideout. Learning that the scrolls contain the coordinates of the treasure of Red Rackham, Tintin and Haddock plan to head there, but Haddock is kidnapped by Allan, who uses him as a hostage to get the scrolls. After rescuing Haddock, Tintin discovers that the treasure is hidden within Marlinspike Hall. There they find the treasure and Thomson and Thompson arrest Allan and
The Secret of the Unicorn Haddock was "the best realised character" in the story, conversely describing the Bird Brothers as "relatively uninspired villains". They went on to state that "The Secret of the Unicorn"-"Red Rackham's Treasure" arc represents "a turning point" for the series as it shifts the reader's attention from Tintin to Haddock, who has become "by far, the most interesting character". They praised the "truly outstanding storytelling" of "The Secret of the Unicorn", ultimately awarding it a rating of four out of five. Phillipe Goddin commented on the scene in the story in which Haddock relates the life of his ancestor, stating that