After visiting a library to uncover the history surrounding the Unicorn, Tintin returns to find the "Unicorn" has been stolen, and suspects Sakharine of stealing it. He heads to Marlinspike Hall with Snowy, where he accuses Sakharine of the theft, but noticing Sakharine's model is not broken, he realizes there are two "Unicorn" models. Tintin returns to his apartment, which has been ransacked, and is shown the metal tube by Snowy. Tintin finds a parchment scroll inside the tube. However, they are interrupted by the arrival of Barnaby, the Interpol officer who had tried to buy the model from Tintin, who is then assassinated while attempting to recover the "Unicorn".