As Tintin pursues a gang of drug smugglers he's locked up in the brig of Kapten Hadag's ship, where the captain is under the influence of the bottle and under the thumb of his dastardly crew. With the scorching Sahara desert at one hand and the depths of the Mediterranean on the other, Tintin and his friends in some dangerously dire straits.

The tomb of Rascar Capac has been unearthed! But one by one, the finders fall into a terrifying coma. Can this be the curse of the Inca gods? Tintin must somehow fathom out the meaning behind his only clue: the shattered crystal ball lying beside each of the victims...

Whilst Tintin and Captain Haddock delve deep into a bloody adventure on the high seas, Snowy discovers a mysterious roll of parchment with a perplexing message. Could this be the key to the secret of the Unicorn?