Tintin buys an old model ship to gift to his friend Captain Haddock. He runs into two strangers, the model ship collector Ivan Ivanovitch Sakharine and a mysterious figure known as Barnaby, who try to convince him to sell it to them. Tintin refuses and returns home. He gifts it to Haddock the next day, who makes a startling admission. The ship is a model of the Unicorn, a 17th-century warship captained by his ancestor, Sir Francis Haddock. Tintin soon discovers that the model is linked to a centuries-old search for the treasure of the infamous pirate Red Rackham. Tintin and Haddock decide to look for the treasure, but to do so they will need to find two other models of the ship, one of which lies in the hands of an unscrupulous pair of antique dealers known as the Bird Brothers. If Tintin and Haddock don’t stay low, they will soon be marked for death.