The Enterprise has received an intern from Starfleet Academy, Amanda Rogers (played by Olivia d'Abo), to study biological sciences under Dr. Crusher, but strange incidents soon begin to occur. In a cargo bay, Commander Riker is nearly hit by a falling cargo crate, which, with a wave of Amanda's hand, swerves to avoid hitting him mid-flight, astonishing the onlookers. Later, when Amanda is in main Engineering, the warpcore suffers a catastrophic meltdown and explodes at the point of the intermix chamber. Amanda is able to repel the plasma/energy wave with nothing more than her hands and reverse the damage to the core. A bemused La Forge remarks to the senior staff that for a second "the laws of Physics went out the window". Suddenly Q materializes and remarks that why shouldn't the laws change, because "they're so inconvenient".
Captain Picard gets Q to admit he is behind the recent Enterprise incidents. He is testing Amanda, who is not human, but actually a Q, meaning that she has inherited the powers of Q. This means she must decide whether to join the continuum or to proceed with a normal human life. Unconvinced, but willing to permit Amanda a chance to make an informed decision, Picard allows Q to teach Amanda how to use her powers. Amanda is particularly keen to learn about her biological parents, who were members of the continuum - they sired Amanda while in human form, but were killed by a tornado in Topeka, Kansas when she was very young. Q shows her how to see an image of her parents and she begins to trust him. They play a game of Q-style Hide and seek, eventually ending up outside the ship on the hull between the warp nacelles (pictured).
Meanwhile on the bridge, a suspicious Picard asks Data to investigate how members of the nearly god-like Q continuum could be killed in a simple tornado, suspecting that Q may have been involved. Picard decides to confront Q with the findings: apparently the rogue tornado had not only managed to escape the weather modification net, but destroyed only Amanda's parents' house before dissipating. Q admits the continuum's involvement, stating that they were a "threat," and that they couldn't be trusted not to use their powers. He further admits that his true mandate from the continuum is to determine whether Amanda is "truly Q" or some sort of "half-human, half-Q hybrid," in which case she is to be terminated. Q eventually softens his stance and presents Amanda with a choice: she can join the continuum, or she can live a normal human life on the condition that she never again use her powers (i.e. the same commitment that her parents had to make).
The Enterprise receives a distress call from a stricken planet nearby - the power net of their ionic pollution systems are failing; if they are shut down, the planet's atmosphere will fill with ionic pollution and sunlight won't be able to reach the surface. Picard sends Commanders Riker and La Forge to help, aware that failure will lead to disaster. Amanda and Q join Picard on the bridge as the two officers endeavor to keep the planetary systems open, but it is clear that they are failing fast. Q taunts Amanda saying that if she doesn't join the continuum she won't be able to resist using her powers. As the reactor fails, Amanda makes a fateful choice and removes all ionic pollution from the atmosphere. Data, who is at Ops, remarks that ionic pollution is now only one part per trillion. Q steps forward to claim Amanda, but she demands time to explain all of this to her adoptive parents. Before they depart, Amanda teleports Dr. Crusher to the bridge to bid her goodbye, saying that she hopes she can return to visit. Dr. Crusher warmly reminds her, "You're a Q. You can do anything you want."