“Noche De Suenos” is episode six of season two of Eureka.
Carter gets doused in toxic waste whilst saving Fargo from a runaway truck. Not that Fargo is terribly appreciative – and he also proves to be an impossible patient. That night he has an embarrassing dream. Then he discovers that Jo had the exact same dream. And they are just the first – lots of people in the town are sharing dreams, which causes problems. Then, it proves to be potentially fatal.
The toxic waste is the first suspect, but that would be too easy. Then, it turns out that Stark is using some dream technology to help Allison share dreams with her son, so that his connection to the artefact can be figured out. This is also a bit too obvious.
They have to find out what is causing these shared dreams before those having them die.