At the conclusion of a trade conference on Betazed, Commander Riker and Troi take shore leave on the planet, while the U.S.S. Enterprise sets out on a routine mission. Shortly after Troi's mother, Lwaxana, interrupts a tender moment between her daughter and Riker, the trio is unexpectedly joined by two Ferengi who had served as delegates at the conference. One of the Ferengi, DaiMon Tog, proclaims that he has come for Lwaxana, who had previously rebuked his amorous advances. As the Ferengi transports out with Lwaxana and Troi, Riker is caught in the beam and is carried away with them.
When the captives awaken aboard a Ferengi ship, Troi and Lwaxana are transported into the lab of Farek, a Ferengi doctor who hopes to study Lwaxana's telepathy through mind probes. Lwaxana gains Troi's return to Riker by agreeing to discuss with Tog a proposal by which he could use her telepathic abilities in trade negotiations.
Meanwhile, Riker entices the Ferengi guard into a chess match, and once outside the cell quickly disarms him. As Lwaxana seduces Tog by rubbing his large and erogenous ears, she receives a telepathic message from Troi and Riker saying that they need an access code to operate the communications system so they can summon help. Lwaxana has nearly extracted the code from Tog when Farek enters, threatening to reveal the incident unless Lwaxana is turned over to him for experimentation.
A message that Riker and Troi are missing summons the U.S.S. Enterprise back to Betazed, where an Away Team discovers flowers indigenous to Ferengi at the spot where they were last seen. Picard orders a scan of all radio transmissions in hopes that Riker has sent a message, but the Ferengi frequency is interrupted by interference. In the midst of the search, Wesley prepares to depart for the Academy to take his Starfleet oral exams. Suddenly realizing that the interference itself may be a signal, he rushes back to the Bridge, causing him to miss his transport ship. The decoded interference reveals the heading of the Ferengi ship, and the U.S.S. Enterprise begins pursuit.
When Troi is overcome with pain, sensing mind probes being used on her mother, an armed Riker enters Farek's lab to free Lwaxana, but a standoff ensues when Tog enters with a phaser. As the Enterprise arrives, Lwaxana buys the release of Troi and Riker by agreeing to aid Tog with her telepathy, and they are returned to the ship. Picard is then forced to play the role of a jealous lover, in order to frighten Tog into returning Lwaxana. For his selfless efforts, Wesley is promoted to full Ensign and is told that he will be allowed to complete his Starfleet courses aboard the Enterprise.