The arbitration, with Data as judge, of a claim by a woman calling herself Ardra that the people of Ventax II owed her their world under a thousand-year-old contract.
In The Next Generation episode Devil's Due, the Enterprise-D answers a call from a Federation science station on Ventax II, where the population is in panic. Legend says that a millennium ago the Ventaxians bought a thousand years of peace from the devil Ardra in return for themselves and their planet, and the term is ending amid tremors and visions.
A woman claiming to be Ardra duly appears, changing shape and vanishing at will, and the Ventaxian leader Jared is ready to submit. She adds the orbiting Enterprise to her claim and takes a fancy to Picard, who is sure she is a fraud. He challenges the contract and both agree to Data as arbitrator.
Picard is losing until La Forge finds her cloaked ship, the source of her tricks. With its power in his own hands, Picard performs Ardra's miracles in court, and she is arrested as a confidence trickster.