The U.S.S. Enterprise is rendered powerless above an unknown and mysterious planet during a mission to repossess a stolen T-9 energy converter from Ferengi culprits. Captain Picard, believing the Ferengi bandits initiated this withdrawal of energy, announces the U.S.S. Enterprise's willingness to resolve the situation. However, the Ferengi vessel reports that it faces the    same predicament.

In an effort to discover who or what has tampered with their  energy supplies, away teams from both the Ferengi and U.S.S. Enterprise starships beam down to investigate the desolate planet.

After a confrontation with the Ferengi enemy, a mysterious being known only as Portal, guardian of the Tkon Empire, materializes before both away teams inquiring, "Who will meet the challenge?" Portal, disenchanted with the Ferengi's barbaric and warlike responses to his inquisition, is intrigued by Commander Riker's wisdom. Once Riker passes several of Portal's intellectual "tests," power is again restored to the respective starships.