Volume 4 includes #9-#11 - "The Crab with the Golden Claws", "The Shooting Star", "The Secret of the Unicorn"
The Crab with the Golden Claws
The book that introduces Captain Haddock! Tintin, Snowy, and the detectives stumble upon an opium-smuggling ring that takes them to Africa aboard the Karaboudjan, Captain Haddock's ship. Haddock is a drunken sot, having been supplied with all the liquor he could possibly want by mutinous drug-smuggling crew members led by villainous First Mate Allan. Escaping from the clutches of Allan and his gang, Tintin and the Captain take a life boat which is fired on by a plane with Moroccan markings...
The Shooting Star
When astronomer Professor Phostle detects an enormous star heading for a collision with the Earth, it looks like everyone is doomed. But the Professor has miscalculated and the huge star brushes past missing narrowly but leaving behind an enormous meteorite which has crashed into Arctic waters. While the Professor was mistaken about the collision there is no mistake about his discovery of a unique new metal present in the meteorite. Tintin, Snowy and Captain Haddock along with a group of scientists are soon on their way to the polar regions where they are to experience some of their most bizarre adventures!
The Secret of the Unicorn
The Thompsons are trying to solve a rash of pockets being picked and Tintin decides to buy on impulse a model of an old galliard ship. But suddenly two other gentleman want to buy the model from Tintin, who refuses because he intends the model to be a gift to his friend, Captain Haddock. Then Tintin finds a small piece of parchment that was hidden in one of the masts talking about a treasure and a ship called the Unicorn. The mystery deepens when it turns out that Sir Francis Haddock, an ancestor of Tintin's good friend, was the captain of the Unicorn. After the captain tells the exciting story of Sir Francis and his glorious victory over the dreaded Barbary buccaneers, Tintin races off to track down the final pieces of the puzzle that will tell where the treasure of the Unicorn can be found.