The Secret of the Unicorn is the eleventh title in the comic book series Designed to be the first volume in a two-part story, the plot of The Secret of the Unicorn was continued in the twelfth Tintin adventure, Red Rackham's Treasure. The comic's revolves around young reporter Tintin, his dog Snowy, and his friend Captain Haddock, who discover a riddle left by Haddock's ancestor, the 17th century Sir Francis Haddock, which could lead them to the hidden treasure of the pirate Red Rackham. In order to unravel the riddle, Tintin and Haddock must obtain three identical models of Sir Francis' ship, the Unicorn, but discover that criminals are also after these model ships, and are willing to kill in order to obtain them.