It all starts in a resort in Vargèse imaginary (Savoy) with Captain Haddock, Tintin reads about a plane crash in the Himalayas. That evening at the hotel, Tintin some sleep while playing chess with the Captain, who is struggling to decide their next move. Tintin has a vivid dream about his friend Chang Chong-Chen Chinese (see The Blue Lotus) waking in the middle of an airplane on fire, and now awake violently, yelling "Chang!" and throwing everything on the table. The next morning, read in the newspaper that Chang was in the plane crash in Tibet. Firmemennte believing that the dream was a vision true, Tintin travels to Kathmandu, followed by a more than skeptical Captain Haddock. They hire a Sherpa named Tharkey, accompanied by several porters, they head to the crash site.
After a series of events, discover large footprints in the snow and Tharkey states that belong to the yeti. The porters left the group, and Tintin, Haddock and Tharkey follow, taking the burden they can. Finally manage to reach the scene of the collision, where Tintin finds a teddy bear, half buried in snow, which seems to be belonging to Chang. Tintin goes through the snow trying to follow in the footsteps of Chang, and finds a cave where Chang carved his name into the rock. Then there is a storm and Tintin falls into a crack in the earth, and rejoins Tharkey Haddock, who had sheltered in the plane crash.
Tharkey decides not to go further, claiming that Chang was dead, and Tintin, Snowy and Haddock continue when Tintin is a scarf on the side of a mountain. Haddock loses his grip and sways dangerously over the abyss. Want Tintin cut the rope that connects them all and be saved, but Tintin refuses the idea, saying that either both or die are saved together. Tharkey, moved by the selflessness of Tintin, returns just in time to save them. They pitch a tent on top, but the strong wind carries it to the face of the yeti. They decide to walk all night, and finally see the monastery of Khor-Biyong. There is a flood, and all three are buried by snow.
Blessed Lightning, a monk of the convent, 'sees' Tintin, Snowy, Haddock and Tharkey in the snow, in a vision. Up in the mountains, Tintin regains consciousness, and unable to reach the monastery, write a note and sends Snowy to deliver it. Snowy start to the monastery but it entertains and lost the note. Snowy finally get the monks to follow.
Captain Haddock wakes up in the monastery. There he meets Tintin and Tharkey again. After Tintin tells the Grand Abbot why they are there, and he advised abandorar the search and return to their country. Lightning tends Blessed another vision, through which Tintin finds that Chang is still alive in a cave, but the "Migou" (the yeti) withheld. Haddock does not believe in the vision, but the abbot explains that much of what is happening in Tibet seems impossible to Westerners. Tintin goes to Charabang, a village in the mountains near where Ray was blessed Chang said. Haddock at first refuses to follow Tintin, but ends up going to Charabang, and both, with Snowy, climb to the "Horn of the Yak" - the site where the monk saw Chang.
Wait until the yeti leaves the cave. Tintin comes with a camera, as the captain had ordered him to take a picture of the yeti could. Inside the cave, Tintin finally finds Chang, who is shivering and fever. Haddock Tintin fails to notify the return of the yeti, and this goes into the cave, Tintin nervous accidentally shoot camera flash. The yeti, frightened by the strong light, runs out of the cave, charging the captain, who was entering the cave. Carried on a stretcher to Chang, it tells the story of his survival, and nursed him as the yeti. Chang called yeti "Poor Snowman" Tintin and was surprised not to say "abominable". "Of course not," Chang says, "He took care of me. But he had died of cold and hunger." Meet again with the Grand Abbot and a committee of monks, that give Tintin a silk scarf in honor of the courage shown, and the strength of his friendship with Chang. They are staying back at the monastery, and after a week, when Chang is recovered, returned to Nepal on horseback. Chang thinks about the yeti is not a wild animal, but has a human soul.