Some time after the events of the first film, the Radcliffe family and their 101 Dalmatian companions prepare to move to a spacious countryside home known as the Dalmatian Plantation. Among them, a puppy named Patch Patch longs to stand out and be special, admiring the daring antics of his television hero, Thunderbolt Thunderbolt. Patch learns of a chance to appear on a show after hearing about an audition, and when he is accidentally left behind as the family travels to the new residence, he sets off for London to chase the opportunity. The audition, however, leaves him overlooked by the producers, while Patch’s determination grows.
Elsewhere in London, the infamous Cruella de Vil Cruella cannot obtain furs due to a probation and restraining order, and she drifts back to her obsession with spots with the help of a French beatnik artist named Lars Lars. To fuel her schemes, she restarts the hunt for the Dalmatians, using a newspaper photo of Patch to locate their new address. Patch’s family realizes he is missing and returns to the city to search for him. Cruella frees her former henchmen, Horace Horace and Jasper Jasper, and sends them in a stolen dog-food truck to seize the remaining puppies. The duo achieves their goal, and the puppies are taken to Lars, who refuses Cruella’s demand to craft a fur coat from the pups, choosing instead to protect them. Enraged, Cruella has Lars bound and gagged and resumes her plan to fashion a Dalmatian fur coat.
The trapped puppies manage to send a Twilight Bark distress call, which is picked up by Patch Patch and Thunderbolt Thunderbolt. They set out to rescue Patch’s family, while Lightning Lightning — Lil’ Lightning — keeps pressuring Thunderbolt into bold, real-life deeds. Thunderbolt is persuaded to take direct action rather than rely on a stealthy approach, a choice that complicates the rescue. Meanwhile, Nanny and the Radcliffes rally to help, and Patch’s parents, Pongo Pongo and Perdita Perdita, join the effort, grateful for the help and the chance to reunite with their children.
As the chase unfolds through the streets of London, the puppies are corralled toward a dramatic showdown. Patch fights to hold the line while the rest maneuver to safety, and Thunderbolt’s course of action leads to chaos on set as the pursuit disrupts filming for Lil’ Lightning’s new show. Cruella and the Baduns close in, but Patch’s courage and quick thinking turn the tide. Thunderbolt makes a dramatic exit, frees himself from danger, and, in a bold move, distracts Cruella long enough for Patch and the others to escape onto a double-decker bus. In a final bid to stop Cruella, Patch uses the vehicle’s momentum to pull off a daring escape, and the pursuing trio of criminals ends up colliding with the river Thames.
The police arrest the Baduns, Lil’ Lightning is taken into custody, and Cruella is restrained and sent away to a mental institution after the chaos subsides. The Radcliffes return home with Nanny’s help, and Patch’s family thanks Thunderbolt Thunderbolt for his role in the rescue, while Thunderbolt downplays his heroics, insisting he’s just an actor. Yet he adds a heartfelt compliment to Patch, calling him “a real, one of a kind wonder-dog.”
In a playful post-credits moment, Patch, now with his 98 siblings, finally gets his chance to shine again on another episode of The Thunderbolt Adventure Hour, signaling that this unique little pup’s dream has not only been imagined but is being realized at last.
