Wil Wheaton

Wil Wheaton is set to guest-star on Syfy's Eureka.

Watch full episodes of Eureka in our Online Video Guide

Wheaton will play Dr. Isaac Parrish, the head of a non-lethal weapons lab and a thorn in Fargo's side. The 37-year-old actor will appear in an episode slated for Friday, July 23.

Wheaton — best known for his roles in Star Trek: The Next Generation and Stand By Me — has also appeared on episodes of The Big Bang Theory, Leverage, Criminal Minds and Numb3rs.

Battlestar Galactica alum joins Eureka

Eureka will debut its fourth season on Friday, July 9 at 9/8c.