Picard's nemesis, Q, returns to wreak more havoc on the U.S.S. Enterprise.
While orbiting Bre'el IV to investigate a descending asteroidal moon which could cause landquakes and tidal waves on the planet, the crew is surprised by the unexpected arrival of Q. Although Picard immediately suspects that the mischievous Q is responsible for the moon's deteriorating orbit, Q admits that his superiors in the Continuum have stripped him of his magical powers and made him human, thus unable to indulge in such chicanery.
Fearful that Q is lying, Picard assigns Data to keep an eye on Q while the crew deals with the perilous situation on Bre'el IV. But Q's presence on board the ship becomes problematic when the Calamarain, a gas-like life form with a grievance against Q, begins attacking him. Picard soon realizes that Q came aboard the U.S.S. Enterprise to receive protection from the Calamarain. But a short time later, the life form attacks Q again and in an attempt to save him, Data sustains serious electrical damage to his android body.
Moved by the injured Data's sacrifice for him, and aware that the crew will be unable to move the moon as long as it must use its shields to protect him, Q steals a shuttlecraft and heads into space, knowing that the Calamarain will follow him. As the force approaches the shuttlecraft, Picard orders the shields to be extended to protect Q, but they are inexplicably inoperative.
Inside the shuttlecraft, another member of the Continuum, Q2, appears beside Q and tells him that he is impressed by his selfless act and gives Q his powers back, but warns that he'll be keeping an eye on him.
A grateful Q suddenly appears on the bridge of the U.S.S. Enterprise with a band and confetti to thank the crew. When Picard asks him to leave, Q obliges, but not before thanking Data by using his newly regained powers to give the android the experience of a human belly laugh. After Q disappears, the crew receives a transmission from Bre'el IV announcing that the moon's orbit has been corrected. Initially confused, the captain realizes that Q has learned a little humanity and saved the planet himself.
Fabulous story, with a great exchange of personalities. This particular escapade has all the makings of a very good (as opposed to just good or otherwise faultless) episode. But what really stands out is the combination of John de Lancie's superlative acting skills and the dialogue written for him. His observations of humanity from within are a wonder to behold, for now we watch him experiencing pain, hunger, nervousness, fear and expectant mortality all in one foul swoop, and doesn't he do it...