The Seven Crystal Balls (originally Les Sept Boules de Cristal) is one of a series of classic comic-strip albums, written and illustrated by Belgian writer and illustrator Hergé, featuring young reporter Tintin as a hero.

The Seven Crystal Balls is the thirteenth in the series.

The storyline

Tintin goes to Captain Haddock's newly acquired estate of Marlinspike, and the Captain says he will do a trick with Tintin. They go to a room, and Tintin's dog Snowy accidentally knocks over Nestor's casks of wine and rum. Snowy is punished accordingly by Tintin, but the captain drags him off. The captain brings out what looks like a glass of water and puts a cylinder over it, with nothing inside, but when he lifts the cylinder, the water is...still water. He says that he and Tintin can go to the show to watch the magician to see how he does the trick. Halfway through a fakir's magical show, a woman's husband is reported sick and the show then breaks up. It turns out that an expedition of travellers went to the Andes to discover Inca tombs, but when they all came back they mysteriously fall into a coma after a crystal ball full of "magic liquid" is smashed nearby. Tintin investigates when Calculus goes missing after putting on a bracelet. The story is continued in Prisoners of the Sun, the next volume in the series.