The return of brilliant former Eureka resident leads to electronic malfunctions.
Calister Raynes ( David Paetkau) was a beloved computer technician with Global Dynamics before leaving Eureka. He had been accused of burning a lab at Global, but Nathan Stark ( Ed Quinn) made sure he was cleared of the charges. Now Raynes has returned after time away and something is not quite right. As Stark tries to help Raynes come to grips with some issues relating to his time at Global, Sheriff Jack Carter ( Colin Ferguson) and Alison Blake ( Salli Richardson-Whitfield) start to see a partner revolving around Raynes. Apparently, a virus has been unleashed on the Eureka computer network and it is related to Ryanes.