From the back of the book:
Located deep in the Adirondack Mountains, PROJECT P.E.G.A.S.U.S. is a top-secret research facility for the U.S. Government’s Department of Energy. Some super heroes have made it their home, such as the THING, QUASAR, DARKHAWK, and the SQUADRON SUPREME. Conversely, some super villains have been imprisoned here, such as ELECTRO, BLACKOUT, and KLAW.
Do your heroes dare to find out what goes on inside PROJECT P.E.G.A.S.U.S.?
This game supplement is designed for use with the MARVEL SUPER HEROES role-playing game. This package includes a 20-page sourcebook describing PROJECT P.E.G.A.S.U.S., its employees and history, and a few enemies. It also includes a poster-map of PROJECT P.E.G.A.S.U.S. and a Gamer’s Handbook of the Marvel Universe entry for one of its long-time residents.