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 cave. He then floods the chamber Tintin and the children are in with water. As soon as the water has reached a device high on the wall, the base will self-destruct. Haddock manages to regain control of the disabled submarine and makes his way to the surface, encountering Thompson and Thomson and the chief of the Syldavian police in a patrol boat. Down below, with all of his men having evacuated the base, Rastapopoulos and his lieutenant leave the base in the submarine. Tintin and the children manage to get free and escape through an airlock in life jackets, just