Star Trek: The Next Generation: Debtor's Planet

When a Vulcan space probe reports that the Ferengi are advancing the people of the planet Megara from a primitive agricultural state to a sophisticated technological society, Captain Jean-Luc Picard and the Starship Enterprise™ are ordered to transport an unlikely passenger to the system, a ruthless twentieth-century businessman who is now a Federation ambassador.
The Ferengi have been changing Megaran culture, turning a hard working and horoable people into vicious xenophobic killers. But the Ferengi are only hired hands. They have hidden masters, with plans to use the Magaran people as a powerful weapon against the Federation.
Now Picard must find a way to use the talents of this new ambassador to free the Megarans. But the ambassador is hididng a deadly secret of his own -- a secret that could unleash an unstoppable destructive force on the Federation.