Shadow of the Hegemon

Shadow of the Hegemon is the second book in Orson Scott Card's Ender's Shadow series, which starts with a sequel to Ender's Game told from mostly from the point of view of Bean, a largely peripheral character in Ender's Shadow. In Shadow of the Hegemon the Battle School graduates, except for Ender, return to their homes on Earth. Ender's brother Peter, acting as his online pseudonym Locke (a conscious nod to John Locke), has caused Ender to return to Earth only to pick up Valentine before leaving for another planet. Shortly after the rest of the Battle School graduates return, the members of Ender's jeesh are kidnapped to be used as strategists in an oncoming world war.

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The person behind the kidnappings, Achilles--the sociopath Bean foiled in the previous novel--attempts to kill Bean and his family, but they avoid the attempt. After Bean discovers an encoded message, he works to rescue Petra and the others while helping Peter come to power under his own name so he can eventually be appointed Hegemon and work against Achilles.

When Peter publishes a column under the Locke pseudonym revealing Achilles for the physopathic muderer he is Achilles is forced to release the rest of the kidnapped Battle Schoolers but takes with him Petra. In India, Achilles plans an invasion of Burma and then Thailand. Most of Battle School graduates that came to Achilles of their own accord, arrange brute force attacks involving long supply lines. Petra arranges a different plan, expecting it never to be used because India could not afford to divert enough of an army from its border with Pakistan to make the attacks as Achilles plans. What she does not know is that Achilles plans to arrange a nonagression pact with Pakistan, leaving the troops free to leave the border. He takes her along as a hostage to the meeting, and deftly arranges just such a treaty.

Nonetheless her plan is not used, but for a different reason than Petra expects: Achilles is secretly working for China, and has arranged to have China attack India after India puts the bulk of its forces along the border of Thailand. At that point, Achilles plans to leave India for China, and continue his efforts towards world domination.

But Bean in Thailand has other plans. With the help of a special force in Thailand, Suriyawong, a fellow Battle Schooler, and Peter "Locke's" distinguished connection, he foils Achilles again, rescues Petra, and along the way, after the murder of Sister Carlotta by-of course-Achilles, learns about the secret of his genius and the doom it will bring him.