While on a charting mission, the Federation starship Enterprise, under the command of Captain Jean-Luc Picard, discovers a zone of pure blackness in space; probes launched into the area simply disappear.

As they continually move closer to study it further, the zone expands and soon envelops the Enterprise, leaving them in a black void with sensors reporting nothing outside.

The crew then detect what appears to be their sister ship, the USS Yamato, approaching them, but it does not respond to hails.

Commander Riker and Lt. Worf beam over to search the ship, where they find it empty with various inconsistencies in its construction, including more seemingly impossible physical loops.

Suddenly, an entity with a distorted, almost childlike face as a result of it attempting to look humanoid, appears in the void, calling itself Nagilum.

As the crew prepares for their end, Picard is tested again by Nagilum through peculiar behavior displayed by doppelgangers of Counselor Troi and Lt.

Picard disagrees, pointing out that their recent encounter shows that both species are curious, a logical statement to which Nagilum concedes before disappearing.