This album is the sequel to the adventure begun in The Secret of the Unicorn. Tintin and Haddock, joined by the Thompsons and Professor Calculus, inventor of a revolutionary submarine, set off in search of the treasure of the Knight of Hadoque. After exploring an island and the wreck of the knight's ship, our heroes find no treasure at all, only a set of strange parchments which, once studied by Calculus, finally reveal the key to the mystery.
Hardcover
