In Biggles Makes Ends Meet, Tidore was a wealthy Syrian merchant residing in Jaffna, Ceylon. He made a complaint to British authorities that his pearling vessel, the Shima had been robbed by pirates and its entire oyster catch taken somewhere around the Nicobar Islands. He also put in an insurance claim for ten thousand pounds for his losses.
Air Commodore Raymond asked Biggles to investigate the case but Biggles was suspicious about Tidore's story from the beginning because of several glaring inconsistencies. For example, why would Tidore be near the Nicobars when the best pearling beds were in the Palk Strait off the coast of Jaffna itself. Why should a wealthy tycoon make such a long sea voyage himself and how could he value his catch when he hadn't even opened his oysters.
Biggles flew to Jaffna with Ginger to interview Tidore and, not surprising, found Tidore evasive and unwilling to provide any more information and refusing to put Biggles in touch with his crew so that he could question them.
Later when Tidore found out that The Count, a senior officer of Colonel Black's had spoken to Biggles and Ginger, Tidore had them brought back to his house, anxious to learn about what the rival gang might have told him. Biggles said the Count had revealed that Tidore had been smuggling gold. Tidore then threatened Biggles that he would not be allowed to leave now that he knew this. But Biggles countered that the rival gang was probably watching his house and should Biggles fail to leave, they would lose no time turning him into the authorities as a convenient way of getting rid of him.
Biggles convinced Tidore that his only option was to tell Biggles all that he knew about Colonel Black's gang. This was his only hope of striking a blow at them, and possibly saving his own life. Tidore had written a letter, hidden in his house, with incriminating facts about the Colonel's gang but Biggles countered that this would not do any good--they would simply kill him to get at the letter. Knowing he was cornered, Tidore agreed to talk but was killed by a knife in his back just as he was about to reveal the location of the Colonel's secret island base in the Nicobars.