h　for　which　he　was　severely　punished。　Feng　Li　resented　this；　sneaked　out　of　the　city；　went　over　to　the　besiegers；　and　told　them　how　the　place　could　be　attacked。

〃The　earth　within　the　Pearly　Gate　is　solid　enough　to　be　tunneled；　and　entrance　can　be　effected　there；〃　said　the　traitor。

So　Feng　Li　was　sent　with　three　hundred　men　to　carry　out　his　plan　under　cover　of　darkness。

After　Feng　Li　had　deserted　to　the　enemy；　Shen　Pei　went　every　night　to　the　wall　to　inspect　the　soldiers　on　duty。　The　night　of　the　sapping　he　went　there　as　usual　and　saw　that　there　were　no　lights　outside　the　city　and　all　was　perfectly　quiet。

So　he　said　to　himself；　〃Feng　Li　is　certain　to　try　to　e　into　the　city　by　an　underground　road。〃

Whereupon　he　ordered　his　troops　to　bring　up　stones　and　pile　them　on　the　cover　of　the　tunnel　opening。　The　opening　was　stopped　up　and　the　attacking　party　perished　in　the　tunnel　they　had　excavated。

Cao　Cao　having　failed　in　this　attempt　abandoned　the　scheme　of　underground　attack。　He　drew　off　the　army　to　a　place　above　the　River　Huan　to　await　till　Yuan　Shang　should　return　to　relieve　the　city。

Yuan　Shang　heard　of　the　defeat　of　Yin　Kai　and　Ju　Gu；　and　the　siege　of　his　own　city；　and　bethought　himself　of　relieving　it。

One　of　his　manders；　Ma　Yan；　said；　〃The　high　road　will　surely　be　ambushed。　We　must　find　some　other　way。　We　can　take　a　by…road　from　the　West　Hills　and　get　through　by　River　Fu；　whence　we　can　fall　upon　Cao　Cao's　camp。〃

The　plan　was　acceptable　and　Yuan　Shang　started　off　with　the　main　body；　Ma　Yan　and　Zhang　Zi　being　rear　guard。

Cao　Cao's　spies　soon　found　out　this　move；　and　when　they　reported　it；　he　said；　〃If　Yuan　Shang　es　by　the　high　road；　I　shall　have　to　keep　out　of　the　way；　but　if　by　the　West　Hills'　by…roa