While rushing to aid the survivors on a planet rocked by a lethal explosion, the U.S.S. Enterprise is stopped by the dangerous "Q" entity who had interfered with their Farpoint mission several months earlier.
The powerful Q demands the Enterprise and crew abandon their rescue mission and partake in a deadly game which, according to Q, could result in either "the greatest possible future" for the crew ... or death!
The game involves surviving a confrontation with fanged, animal soldiers created by Q. Strangely, the major player in the game turns out to be Commander Riker, who is given Q's power and offered full membership in his continuum. After using his new-found power to save Wesley and Lt. Worf from the hostile creatures, Riker meets with the crew to discuss Q's proposal.
After the meeting, Q tempts Riker by telling him that if he joins the continuum, the Commander can use his powers to give his friends anything they want. Captain Picard, having faith in his crew's resistance to temptation and their common sense, urges Riker to accept Q's offer. Riker obliges by turning Wesley into a 25-year-old Starfleet officer, restoring Geordi's vision, creating a female Klingon companion for Lt. Worf and offering Data the chance to be human. However, to Q's disbelief and Picard's pleasure, the crew members decline the gifts because of their disreputable origin. Thwarted again by the integrity and ingenuity of humans, Q disappears, thereby returning Riker to his normal condition.