LewisreturnstoOxfordafterseveralyearsabsenceandisreluctantlyassignedbyhisnewboss,DCSInnocent,tothemurderofanOxfordmathematicsstudentwhowasshotwhileparticipatinginasleepstudy.Thekey-codeusedtoaccessthesleeplabwasassignedtoafellowmathsstudent,DanielGriffin,butDanielsautomotiveempire.Heisdisruptiveandhasnorespectforhisunclewhonowheadsthecompany.ThefutureofthecompanyhoweverrestsonanimpendingdealwithJapaneseinvestorswhoinsistthatfamilyunityisallimportantatthistime.Whentwoothermurderoccurs,Lewismustdecipheracrypticclueleftinanoldcasefilebyhisformerboss,ChiefInspectorMorse.
