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
Tintin and the Lake of Sharks his every move), and the Captain and the detectives play a game of golf, Snowy runs into a frogman who has obtained from Madame Black some plans stolen from Calculus' laboratory. The frogman escapes by jumping into the lake, but Snowy manages to bite off a part of one of his flippers. After the Captain and the detectives tell Tintin what has happened, he gives the dogs the bitten-off flipper to sniff. While Gustav leads Haddock to a pile of abandoned tires, Tintin follows Snowy to a buried chain which, when pulled, opens a passage to a hidden cave where