Xu You produced the captured letter； saying； 〃Who wrote that？〃
〃Where did you get it？〃
Whereupon Xu You told Cao Cao the story of the captured messenger。
Cao Cao seized him by the hand； saying； 〃Since our old friendship has brought you to me； I hope you have some plan to suggest to me。〃
Xu You said； 〃To oppose a great army with a small one is to walk in the way of destruction； unless you inflict quick defeat。 I can propose a plan which will defeat the innumerable hordes of Yuan Shao without fighting a battle。 But will you follow my advice？〃
〃I very much desire to know your plan；〃 said Cao Cao。
〃Your enemy's stores of all kinds are at Wuchao； where the mander of the guard is that drunkard Chunyu Qiong。 You can send some of your trusty veterans to pretend they belong to one of Yuan Shao's generals； Jiang Qi； sent to help guard the depot。 These soldiers can find an opportunity to fire the grain and stores of all kinds； which will upset all Yuan Shao's calculations。 In three days Yuan Shao is no more。〃
Cao Cao greatly approved。 He treated Xu You very liberally and kept him in his camp。 Forthwith he chose five thousand of horse and foot ready for the expedition。
Zhang Liao protested； saying； 〃The enterprise will be futile as the grain depot will certainly be well guarded。 Without caution； we may be victims of the treachery on the part of the newly arrived Xu You。〃
〃Xu You is no traitor；〃 said Cao Cao。 〃He has e sent by Heaven to defeat Yuan Shao。 If we do not get grain； it will be hard to hold out。 I have to either follow his advice or sit still and be hemmed in。 If he were a traitor； he would hardly remain in my camp。 Moreover this raid has been my desire for a long time。 Have no doubts： The raid will certai