Tintin and the Blue Oranges

Professor Calculus broadcasts on a black-and-white TV from Marlinspike Hall to appeal for help end world hunger. He receives many letters and parcels, among them a mysterious blue orange from Zalamea that can grow in desert conditions and glows in the dark, though no explanation accompanies it. That night, two thieves break into Marlinspike Hall and steal the blue orange.

Calculus, Tintin, Haddock and Snowy set out for Valencia to pursue Zalamea's blue orange and its puzzling mission. The group heads toward the Spanish city, noted for filming locations such as Burjassot, Simat de la Valldigna (Monastery of Santa María de la Valldigna), Gandia and Xàtiva.

Upon arriving at Zalamea's hacienda, Calculus is absent and the group is met by Zalamea's cousin. They learn that Zalamea has kidnapped Calculus to help perfect the blue oranges, which mature with neutron bombardment in five days but taste bitter and salty. The plan suggests a dangerous scientific edge that fuels the conflict.

Tintin befriends a local boy who leads him to a gang hideout, where he learns a courier intended to deliver Zalamea's parcel was attacked by a man bearing a blue dragon tattoo on his hand. The hint deepens the mystery surrounding the blue orange and its handlers.

Detectives Thomson and Thompson arrive from Interpol to investigate Zalamea's disappearance. They encounter an unfortunate bull incident that underscores the danger closing in on the characters.

Tintin and Haddock go to Fernando's hotel, Tintin picks the lock, and overhears him speaking on a radio to his chief about a rendezvous. They tail him only to be knocked unconscious and captured.

Thomson and Thompson check into a hotel but are tricked by the villains who use doubles to coax them from their rooms. Tintin and Haddock regain consciousness in a grain silo and Snowy rescues them by dropping a rope.

Back in town, Tintin and Haddock are chased by police around a busy market. They escape thanks to the intervention of Bianca Castafiore.

A delegation from the visiting Emir of Sakali arrives, and Tintin and Haddock reunite with their young friends. They decide to sneak back into Zalamea's hacienda to test new information about Estensoro's role in the kidnapping.

In Zalamea's hacienda they use animals with pans tied to their tails as distractions while searching Estensoro's room. They discover a radio identical to Fernando's and, after Haddock drinks Estensoro's whisky, find secret documents that raise their suspicions about their enemies.

The professors broadcast their whereabouts from the villains' hideout, triggering Estensoro to rush to inform his boss. Tintin and Haddock also hear the broadcast and set off in pursuit, but the professors remain missing.

Snowy finds an agal belonging to one of the Arab kidnappers, revealing the Emir of Sakali as the same man described by Zalamea. The Emir's yacht anchors at the docks, and Tintin and Haddock attempt a rescue but are drugged; a climactic fight ensues as the children rally to help and the Emir is subdued as police arrive.

All is well as they return to Marlinspike Hall for a celebration and photos. They hope to perfect the oranges within ten years and possibly grow other crops in the desert; Thomson and Thompson crash into a fountain in a closing gag, as greedy dogs eat the 'THE END' sign.