When Tintin stumbles across a model ship at the Old Street Market, he buys it as a gift for his friend Captain Haddock. But this isn't just any old model ship ...it's the Unicorn. Built by one of Haddock's ancestors it holds a clue to finding the treasure of a notorious pirate. The Secret of the Unicorn: When Tintin stumbles across a model ship at the Old Street Market, he buys it as a gift for his friend Captain Haddock. But this isn't just any old model ship... it's the Unicorn, built by one of Haddock's ancestors, and it holds a clue to finding the treasure of a notorious pirate!