t　their　prows　pointed　east　and　to　go　closer　in　so　that　many　arrows　might　hit　them。

Zhuge　Liang　ordered　the　drums　to　be　kept　beating　till　the　sun　was　high　and　the　fog　began　to　disperse；　when　the　boats　got　under　way　and　sailed　down　stream。　The　whole　twenty　boats　were　bristling　with　arrows　on　both　sides。

As　they　left；　Zhuge　Liang　asked　all　the　crews　to　shout　derisively；　〃We　thank　you；　Sir　Prime　Minister；　for　the　arrows！〃

They　told　Cao　Cao；　but　by　the　time　he　came；　the　light　boats　helped　by　the　swift　current　were　seven　miles　long　down　the　river　and　pursuit　was　impossible。　Cao　Cao　saw　that　he　had　been　duped　and　was　very　sorry；　but　there　was　no　help　for　it。

On　the　way　down　Zhuge　Liang　said　to　his　panion；　〃Every　boat　must　have　five　or　six　thousand　arrows　and　so；　without　the　expenditure　of　an　ounce　of　energy；　we　must　have　more　than　ten　myriad　arrows；　which　tomorrow　can　be　shot　back　again　at　Cao　Cao's　army　to　his　great　inconvenience。〃

〃You　are　really　superhuman；〃　said　Lu　Su。　〃But　how　did　you　know　there　would　be　a　thick　fog　today？〃

〃One　cannot　be　a　leader　without　knowing　the　workings　of　heaven　and　the　ways　of　earth。　One　must　understand　the　secret　gates　and　the　interdependence　of　the　elements；　the　mysteries　of　tactics　and　the　value　of　forces。　It　is　but　an　ordinary　talent。　I　calculated　three　days　ago　that　there　would　be　a　fog　today；　and　so　I　set　the　limit　at　three　days。　Zhou　Yu　would　give　me　ten　days；　but　neither　artificers　nor　materials；　so　that　he　might　find　occasion　to　put　me　to　death　as　I　knew。　But　my　fate　lies　with　the　Supreme；　and　how　could　Zhou　Yu　harm　me？〃

Lu　Su　could　not　but　agree。　When　the　boats　arrived；　five　hundred　soldiers　were　in　readiness　on　the　bank　to　carry　away　the　arrows。　Zhuge　Liang　bade　them　go　on　board　the　b