As the alien galactic council debates the fate of humanity while examining a space probe filled with the essence of human secrets, they face a dilemma: should they destroy Earth or integrate humans into their interstellar community? To test the integrity of this strange species, they inexplicably bestow unparalleled power upon one unsuspecting soul. This individual turns out to be Neil Clarke, an overlooked teacher residing in London.
At first, Neil is blissfully unaware of the extraordinary abilities at his disposal. His initial desire is rather vindictive—wanting his least favorite students to be eliminated by alien technology. This wish is swiftly granted, throwing his life into chaos as he learns that he can manifest any whim. In a frantic attempt to rectify the chaos he has unleashed, Neil inadvertently animates the deceased as flesh-eating zombies; although he manages to reverse this blunder and erase the entire incident soon after.
As he grapples with this mind-bending power, Neil begins to make increasingly personal requests, including bestowing his friend Ray with the adoration of Miss Pringle, or allowing his beloved dog, Dennis, to speak. However, his well-intentioned actions quickly devolve into selfish desires, highlighted by his wish for Catherine West to fall desperately in love with him, a request that ultimately fails due to technological hiccups.
The evening takes a twist when Catherine unexpectedly visits Neil, blissfully ignorant of the cosmic forces at play. Their intimate rendezvous is soon compromised by her obsessive ex, Colonel Grant, who inadvertently witnesses their time together.
Catherine soon discovers that Dennis has declared his affections for Neil, which leads her to wrongly assume that Neil is already committed. Meanwhile, Ray divulges that Miss Pringle's devotion resembles more of a worshipful fixation than genuine romance. In a twist of fate, Catherine takes it upon herself to imprison Grant in her apartment but not before Neil exacts a playful vengeance by breaking and later healing the colonel's arm.
The truth about Neil's powers spirals out of control when Grant kidnaps him and restrains him to prevent an escape. The beleaguered teacher is compelled to grant outlandish requests, such as gifting oversized ears and webbed feet to English citizens or dressing police officers in flamboyant pink uniforms.
As Catherine and Ray rescue Neil from the clutches of Miss Pringle’s obsessive following, Neil tries to flip the chaos back over, though his optimism is fleeting. Disillusioned by his ability to shape reality, he resolves to address global issues with his powers. He wishes for endless food for all, the eradication of wars, and the realization of every individual's dreams.
However, these noble attempts at creating a utopia go horrifically awry, leading to a worldwide epidemic of obesity, overpopulation with houses, irrational wars, and eventually, an approaching global ice age. Aware of the repercussions his whims have wrought, Neil attempts to reverse the wishes but finds himself distraught over his failures to enhance his personal life and the futility of his altruistic aspirations.
In a heart-wrenching climax, Neil reaches a point of desperation, contemplating ending his own life, only to be interrupted by Dennis leaping into the Thames after him. In the midst of saving both himself and Dennis, Neil grasps the weight of his recklessness. Dennis imparts the wisdom: > “You should give the power to me, because I never think of anything selfish.” This epiphany prompts Neil to relinquish his powers to Dennis, inspired by his friend's selflessness.
Meanwhile, the alien council, observing the tumultuous events on Earth, deem the planet unworthy. Their warped morality—where dominance is deemed virtuous and weakness shunned—stands in stark contrast to Neil’s ideals of peace and unity. As they conclude that Earth must be destroyed, Dennis quickly wishes for the obliteration of the source of power, resulting in a catastrophic backlash that obliterates the alien ship.
Stripped of their powers but lifted by newfound conviction, Neil bravely asks Catherine out for a date. Miraculously, she accepts his invitation. Just as everyone breathes a sigh of relief, it becomes evident that Dennis retains a measure of this power, having wished only for the destruction of their power source. This revelation sets the stage for an exciting new chapter in the ongoing tale of humanity's struggles and self-discovery.
