Tintin is a young Belgian reporter and adventurer who becomes involved in dangerous cases in which he takes heroic action to save the day. The Adventures may feature Tintin hard at work in his investigative journalism, but seldom is he seen actually turning in a story.
Readers and critics have described Tintin as a well-rounded yet open-ended, intelligent and creative character, noting that his rather neutral personality—sometimes labelled as bland—permits a balanced reflection of the evil, folly, and foolhardiness, which surrounds him. The character never compromises his Boy Scout ideals, which represent Hergé's own, and his status allows the reader to assume his position within the story, rather than merely following the adventures of a strong protagonist.[37] Tintin's iconic representation enhances this aspect, with Scott McCloud noting that it "allows readers to mask themselves in a character and safely enter a sensually stimulating world."
Snowy (Milou in Hergé's original version), a white Wire Fox Terrier dog, is Tintin's loyal, four-legged companion. The bond between Snowy and Tintin is very deep, as they have saved each other from perilous situations many times. Snowy frequently "speaks" to the reader through his thoughts (often displaying a dry sense of humour), which are not heard by the human characters in the story. Snowy has nearly let Tintin down on occasion, particularly when distracted by a bone. Like Captain Haddock, he is fond of Loch Lomond brand Scotch whisky, and his occasional bouts of drinking tend to get him into trouble. When not distracted, Snowy is generally fearless, his only fear being arachnophobia. When Tintin gets tied up by villains (which often happens), Snowy is usually able to free him by gnawing through the rope
Captain Archibald Haddock (Capitaine Haddock in Hergé's original version) is a Merchant Marine sea captain and Tintin's best friend. Introduced in The Crab with the Golden Claws, Haddock is initially depicted as a weak and alcoholic character, but later evolves to become genuinely heroic and even a socialite after he finds a treasure from his ancestor, Sir Francis Haddock (Chevalier François de Hadoque in the original version). The Captain's coarse humanity and sarcasm act as a counterpoint to Tintin's often-implausible heroism; he is always quick with a dry comment whenever the boy reporter seems too idealistic. After he and Tintin find Red Rackham's treasure, Captain Haddock lives in the luxurious mansion Marlinspike Hall (Le château de Moulinsart in the original French).
The hot-tempered Haddock uses a range of colourful insults and curses to express his feelings, such as "billions of billious blue blistering barnacles" or "ten thousand thundering typhoons", "bashi-bazouk", "visigoths", "kleptomaniac", or "sea gherkin", but nothing actually considered a swear word. He is a hard drinker, particularly fond of rum and of Scotch whisky, especially Loch Lomond; his bouts of drunkenness are often used for comic effect, but sometimes get him into serious trouble.
Professor Cuthbert Calculus (Professeur Tryphon Tournesol in Hergé's original version; tournesol is the French word for "sunflower") is an absent-minded and partially-deaf physicist and a regular character alongside Tintin, Snowy, and Captain Haddock. He was introduced in Red Rackham's Treasure, and based partially on Auguste Piccard, a Swiss physicist.[39] The leading characters do not initially welcome his presence, but through his generous nature and his scientific ability, he develops a lasting bond with them. Eventually, by the end of Land of Black Gold, he becomes a resident of Marlinspike Hall. Normally mild-mannered and dignified, Calculus occasionally loses his temper and acts in a spectacularly aggressive manner in response to actual or perceived insults, such as when Captain Haddock belittles his work or accuses him of "acting the goat". He is a fervent believer in dowsing, and carries a pendulum for that purpose. Calculus's deafness is a frequent source of humour, as he repeats back what he thinks he has heard, usually in the most unlikely words possible. He does not admit to being near-deaf and insists he is only "a little hard of hearing in one ear."
Young journalist Tintin and his dog Snowy are browsing in an outdoor market in 1940s England. Tintin buys a miniature model of a ship, the Unicorn, but is accosted by an Interpol officer, Barnaby, and a ship collector, Ivan Ivanovitch Sakharine, who both unsuccessfully tried to buy the model from Tintin. Tintin takes the ship home, but it is accidentally broken in an incident between Snowy and a cat. A parchment scroll slips out and rolls under a piece of furniture. Meanwhile, bumbling police detectives Thomson and Thompson are on the trail of a pickpocket, Aristides Silk.
After visiting Maritime Library to uncover the history surrounding the Unicorn, Tintin returns to find that the Unicorn has been stolen, suspecting Sakharine. He visits Marlinspike Hall and accuses him of the theft. After arguing, Tintin begins to notice that Sakharine's model is not broken, realizing that there are two Unicorn models. After returning home once again, Tintin finds out that his apartment had been ransacked. Snowy shows him the scroll but shortly after reading an old message written on it, they are interrupted by the arrival of Barnaby, who is then assassinated while attempting to recover the Unicorn. Tintin places the scroll in his wallet, but it is stolen by Silk the next morning, after a scuffle with the police detectives.
Later, Tintin is abducted by accomplices of Sakharine, and imprisoned on the SS Karaboudjan. He learns that Sakharine formed an alliance with the ship's staff and led a mutiny to take over control. On board, Tintin meets Captain Haddock, the ship's captain. Haddock is permanently drunk and thus unaware of the happenings on board his ship. Tintin, Haddock, and Snowy eventually outrun the crew and escape from the Karaboudjan in a lifeboat. The ship fails to ram their boat because they instead rammed an empty lifeboat the captain accidentally released during his escape. Presuming them to have survived by the number of lifeboats, Sakharine sends a seaplane to find and capture them. The trio seizes the plane, and use it to fly towards the fictitious Moroccan port of Bagghar. However, the seaplane crashes in the desert due to low fuel. While trekking through the desert, Haddock hallucinates, and remembers facts about an ancestor of his, Sir Francis Haddock, who was a 17th-century captain of the Unicorn. Sir Francis's treasure-laden ship was attacked by the crew of a pirate ship, led by Red Rackham and after his eventual surrender, Sir Francis sank the Unicorn, and most of the treasure, to prevent it from falling into Rackham's hands. It implies that there were three Unicorn models, each containing a scroll; together, the scrolls can reveal coordinates of the location of the sunken Unicorn and its treasure. The third model is in Bagghar, possessed by Omar ben Salaad. Sakharine causes a distraction in a Bianca Castafiore concert that results in him successfully stealing the third scroll. After a chase through the city, he gains all the scrolls by having his men toss Captain Haddock and Snowy in the water, to force Tintin to go after them instead of saving the scrolls. After the boat leaves, Tintin is ready to give up but is persuaded by Haddock to continue. With help from officers Thompson and Thomson, Tintin and Haddock track Sakharine down, who is revealed to be a descendant of Red Rackham. They head back to port and set up a trap, but Sakharine uses his pistol to resist arrest. When his men fail to save him, Sakharine challenges Haddock to a final showdown. Sakharine and Haddock sword-duel with cranes and swords eventually resulting in Sakharine being defeated and pushed overboard by Haddock. When climbing ashore, Sakharine is arrested by Thomson and Thompson. Guided by the three scrolls indicating the location of Marlinspike Hall, Tintin and Haddock find there some of the treasure and a clue to the Unicorn's location. Both men agree on setting up an expedition to find the shipwreck.