Project Pegasus will become Thing’s first full-time job, outside of being a member of the FF. These issues introduce the facility as a place that studies super-villains (and basically houses them as a prison). Think Gitmo for powered baddies.
In this story, Thing finds out that the childlike Wundarr has been taken to Pegasus, and he goes there to break him out. Thing still feels protective of the man-child. Captain America is there to defend the facility from Thing.
We learn that the Pegasus scientists are trying to harness Wundarr’s power so they can reactivate the cosmic cube, which they also have in their possession.
Inevitably, a villain shows up, hypnotizes Cap, and steals the cube. He ends up hiding in Man-Thing’s swamp.
Manny gets a hold of the Cube, and it gets returned to Pegasus.
Here’s a map!