TheworldfamousKarthoumdiamond,whichisworthsome2millionextremelyhardDutchGuilders,isbeingtransportedtotheNetherlandsfromPretoriatobeondisplayinamuseum.DirectorSondagfeelsthediamondisn`tgettingenoughprotectionandresortstohiringaprivatedetectivetokeepaneyeonit.Unfortunatelyforhim,someItalianmobstersareplanningajewelheistandmakesureSondaghiresthebumblingandincompetentSherlockJones.Infact,Sherlock`sbassethoundWatsonhasabettergraspofthesituationthanhismaster.