“The Ex-Files” is episode eight of season four of Eureka.
In the previous episode, “Stoned”, Dr Grant was approached by Beverley Barlowe, who has returned. She is apparently the daughter of a colleague of Grant’s from the 40s – the man whose heart Allison restarted in “Founder’s Day”.
Tess appears in Global Dynamics, as Allison is having a conversation with Carter, and gets a bit stroppy. Carter, meanwhile, discovers Stark in his office – despite the latter having vaporised or something in “I Do Over”.
There seem to be some serious potential problems – only the people they are seeing are hallucinations, and several other people are having them too.
Beverley, meanwhile, wants Grant to sabotage a weapons project that GD is working on, and several things around town are destroyed.