Kai Caster

Jess, Schmidt, and Winston go to Chicago with Nick to help him deal with a death in his family.

The discovery of a disembodied human brain at the scene of a car crash gives the CSI team a few headaches: it does not belong to any of the victims. Whose brain was it, and what is it doing by the roadside? DB Russell is also concerned his son is not focused on college following his suspension from school.

Magnum's uncle visits and reveals a shocking secret about Thomas' mother; TC asks Higgins for help when he realises he may have witnessed a potential murder from his helicopter; Higgins decides it's time to tell Ethan the truth about her past.