反间之计

Explanation: Date: alienate. Intended for the use of the enemy's spy informed the enemy off the plan to make mistakes. Later that divide the enemy, so that is not the unity of plan. 　　Source: "Inter-grandchildren with" anti-room who, because of its among the enemy and use it. " 　　Examples: Kai said: 'This is Zhuge Liang ~, Yuling me they do not know. '"(Ming Luo," Three Kingdoms "eighty-seventh back)