In 2375 Picard defied orders to stop a Federation-Son'a plan to relocate the Ba'ku and harvest the regenerative particles in their planet's rings.
The 600 Ba'ku lived on a planet whose rings gave off metaphasic radiation, which kept them young and healthy. In 2375 Admiral Matthew Dougherty agreed with the Son'a, led by Ru'afo, to secretly move the Ba'ku off the planet so the particles could be collected. The process would make the planet uninhabitable for generations.
The plan came to light when Data, observing the Ba'ku in secret, was damaged and exposed a hidden Federation team. Picard learned the truth and, believing the relocation was wrong, defied his orders and went to defend the Ba'ku with several of his crew.
Picard found that the Son'a were themselves Ba'ku who had been exiled a century earlier after a failed rebellion. Ru'afo killed Dougherty and tried to finish the collection, but Picard stopped him, and Ru'afo died when the collector exploded. The Son'a were invited to reunite with their families.