Tintin is interested in the death of a sailor found drowned in a port. This death has to do with an empty box than crab Snowy found in a trash can. It was discovered in sailor clothes a message written on a piece of paper that was part of the package of this tin can. This message contains a word "Karaboudjan," which happens to be the name of a cargo ship. Tintin investigates the ship, but he soon held captive on board by the crew. He later discovered that the freight cans contains no crab but opium. In seeking to escape he meets Captain Haddock, theoretically master on board, but that is maintained intoxicated by his lieutenant Allan, the latter having been able to get master on board. This album is one of the finest and funniest of the series, especially because it introduced so strong humorous captain, who will become the inseparable companion of Tintin and will establish a high-point against human qualities and defects facing the boyscout naivety of Tintin.