The Peacekeepers (Star Trek: The Next Generation, Book 2)

While Captain Picard and the crew of the U.S.S. Enterprise^TM search feverishly for the missing crewmen, Data and LaForge discover they are in a station almost identical to the one they were exploring, high in orbit around an Earth-type world. Years before, the occupants of that planet accidentally stumbled onto the ship and its advanced technology -- and since then have used its weapons to keep the nations on the planet below disarmed, and at peace.

Now their own arrival has precipitated a crisis on the station. Somehow, Data and LaForge must find a way to restore trust between the planet below and the station's guardians up above -- before a final, destructive war breaks out!