SergeantVoighttriestofindoutwhoisbehindthemurderofJin,andcomeupwiththeunbelievablediscoveryandlearnedthatSergeantEdwinStillwellplayingadoublegamewiththeintentionofgettingoutonthesurfaceofthebigfishalongwithVoight.Inthemeantime,allmembersoftheintelligencedepartmentsreceivedeaththreatsfromanunknowngroupcalled"Shadow".AtseveralplacesinChicagoinafire,explosion,androbbery,forwhich"Shadow"takeresponsibility,bringingthecityintochaoseee