“Insane in the P-Brane” is episode eleven of season three of Eureka.
Carter meets Dr. Tess Fontana, the new head of Section 5 (and a friend of Allison’s) – which has been reopened – under less than brilliant circumstances, when he almost crashes into her car which she has apparently left in the middle of the road. Not the best start to a relationship.
At Global Dynamics, one of the staff members is convinced the place is haunted. This doesn’t get much belief – then objects start moving of their own accord. During a tour of Section 5, something happens to Carter and Tess, leaving them apparently stranded in another dimension.
The new underlying plot thread, replacing those of the artefact and the bunker, would appear to be the signal – which seems to be extraterrestrial in nature.