The 60th anniversary of Eureka becomes life-changing in more ways than one when a marriage proposal is eclipsed by a mysterious transport to a military site and a new face in the crowd.

Dr. Isaac Parrish, the brilliant director of the Non-lethal Weapons Lab, is feeling a little undervalued these days. Then all his latent hostility goes viral, infecting everyone with such fury that no one is safe, especially Fargo.