r　the　battle　array　and　released　him。　The　leader　was　Sima　Wang。

But　although　Deng　Ai　had　been　rescued；　his　nine　camps　were　seized　by　his　enemy　and　he　had　to　retire。　He　led　his　army　to　the　south　of　River　Wei　and　made　a　camp。

〃How　did　you　know　exactly　where　to　strike　in　that　maze？〃　asked　Deng　Ai　of　his　rescuer。

Sima　Wang　replied；　〃In　my　youth　I　went　to　study　in　Jingzhou　and　was　friendly　with　Shi　Guangyuan　and　Cui　Zhouping。　They　explained　that　formation　to　me。　Jiang　Wei　used　what　is　known　as　'The　Serpent　Coil'；　and　the　only　way　to　break　it　is　to　attack　the　head；　which　I　saw　was　in　the　northwest。〃

Deng　Ai　replied；　〃Although　I　have　studied　formations；　I　do　not　know　all　the　modifications。　But　since　you　know　about　this；　we　may　be　able　to　recover　our　camps。〃

〃I　fear　the　little　I　have　learned　will　not　be　enough　to　overe　Jiang　Wei。〃

〃Tomorrow　you　shall　contend　with　him；　and　while　his　attention　is　engaged；　I　will　attack　the　rear　of　Qishan；　and　we　will　recover　our　camps。〃

So　a　force　was　prepared　to　attack　on　the　morrow；　and　Deng　Ai　sent　a　letter　of　challenge　to　a　contest　in　tactics　for　the　same　day。　Jiang　Wei　marked　in　to　accept。

Jiang　Wei　said　to　his　officers；　〃In　the　secret　book　that　I　received　from　the　Prime　Minister；　the　variations　of　the　formation　are　three　hundred　and　sixty…five；　corresponding　to　the　circuit　of　the　heavens。　This　challenge　from　them　is　as　one　going　to　teach　hewing　to　the　God　of　Carpenters。　I　think　some　ruse　lies　behind　this。　Can　you　guess　what　it　is？〃

Liao　Hua　replied；　〃While　they　engage　your　attention　in　this　petition；　they　intend　to　attack　our　rear。〃

〃Just　so；　that　is　also　my　opinion；〃　replied　Jiang　Wei。

So　he　prepared　a　counter…stroke　by　sending　Liao　Hua　and　Zhang　Yi　to　lie　in　wait