Complex sentence: The teams are unable to find him and close down the hunt, while discovering his make-shift lab in the building's basement; from the numerous valuables in the lab, the Fringe team determines that Eugene had been silently watching the residents.
Split into simpler sentences: The teams are unable to find him and close down the hunt, but not before discovering his makeshift lab in the building's basement. From the numerous valuables in the lab, the Fringe team determines that Eugene had been silently watching the residents.