简介：ItreturnssixmonthsaftertheshockingfinaleofSeason3,andtheteammustovercometheirgrieftotackleadangerouscrimewave. Thistime,theglovesarewellandtrulyoffforProfessorTinhislecturesandanewmusicalpursuit,romanceisverymuchaliveforhismotherAdelaideTempest(DelaTour),andthelinesbetweenprofessionalandpersonalbecomeblurredfortherapistHelenaGoldberg(Stevenson). Meanwhile,DIMaiyaGoswami(SunetraSarker)takeschargeofthepoliceforcewithseriesfavoriteDSDanWinters(White)fiercelyatherside.