How did pizarro's act of taking atahualpa hostage force the inca to do what pizarro wanted?

In 1530, Pizarro come back to Panama. In 1531, he cruised down to Peru, arriving at Tumbes. He drove his armed force up the Andes Mountains and on November 15, 1532, achieved the Inca town of Cajamarca, where Atahuallpa was appreciating the hot springs in planning for his walk on Cuzco, the capital of his sibling's kingdom.

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