In the space-age world of tomorrow, the two iconic families collide in a clever, time-bending adventure. Elroy Jetson (voiced by Daws Butler) is tinkering away on a time machine, while his father, George Jetson (voiced by George O'Hanlon), is hauled into Mr. Spacely’s office for a serious talk. The boss’s rival, Cogswell, has been stealing ideas, and Spacely suspicions that George might be helping him. To save his job, George is ordered to spy on Cogswell. What starts as a simple assignment spirals into a broader scheme when George uncovers that Cogswell’s robot computer, S.A.R.A. (voiced by Patric Zimmerman), has been wheedling secrets from Spacely’s own robot, R.U.D.I. (voiced by Don Messick). The plot thickens as R.U.D.I. sabotages George’s attempts to report the breach, leaving the innocent Jetsons caught in the middle of corporate intrigue.
On the prehistoric side, Wilma Flintstone (voiced by Jean Vander Pyl) and Betty Rubble (voiced by Julie McWhirter) push Fred Flintstone (voiced by Henry Corden) to plan a vacation in Honolurock, hoping for a break from the daily grind. Fred, however, is more focused on work and the impending poker tournament at the Water Buffalo Lodge, where he and his buddy Barney Rubble (Barney Rubble) weigh the odds. Mr. Slate (voiced by John Stephenson) arrives with bad news: the late shift is mandatory, threatening their chance at time away. The men decide to improvise, disguising themselves to slip away to the tournament, but mischief follows. A spider—an odd, comic obstacle—helps expose their ruse, and Mr. Slate fires Fred and Barney for their disobedience. The seeds of trouble are planted as both worlds collide around a dependence on loyalty, pride, and the pressure to perform.
Meanwhile, Elroy’s machine is ready, and the Jetsons decide to take a trip to the 25th Century for some much-needed rest and relaxation. The time machine whisks them into a campfire of fate where future tech meets Stone Age sensibilities. The Flintstones extend a warm welcome, and friendship blooms between Fred and George as the Jetsons show off a suite of gadgets that astound Wilma, Betty, and their friends. To help Mr. Slate win a company picnic, Fred and George Cousin-ize their chemistry of gadgets, presenting George as a distant relative and letting technology work its magic. The plan pays off in a string of competitive events where George’s genius seems to tilt the odds, but the chaos of the situation—Astro and Dino’s antics—decides the final outcome, tipping Turk Tarpit (voiced by Hamilton Camp) to victory and reinforcing the fragility of trust. Fred and Barney are once again left without their jobs, but their bond remains.
As the two worlds marvel at their unlikely alliance, Henry Orbit (voiced by Daws Butler) and Rosie the Robot Maid (voiced by Jean Vander Pyl) assemble a “time machine retriever” to fetch the Jetsons back home. When the machine is activated, the result is a surprising return: the Flintstones arrive, publicized to the press, startling Mr. Spacely and his entourage. The confusion of past and future deepens as George searches for a job in this scrambled reality. He’s offered a partnership with Mr. Slate, and the two men work to stabilize a situation that could redefine their careers. The Jetsons’ modern sensibility clashes with Fred and Barney’s Stone Age pragmatism, and the families must navigate newfound fame, business maneuvering, and the delicate balance of work and friendship.
With the Jetsons back in the picture, Mr. Spacely’s ambition takes a new shape as he uses Fred as a spokes-caveman to promote his Stone Age-inspired vehicles. But secrets leak: R.U.D.I. reveals investor information to S.A.R.A., and the tangled web of loyalties strains old friendships. Cogswell, watching the chaos, sends his robotic dog Sentro (voiced by Patric Zimmerman) to steal the designs, while S.A.R.A. pushes R.U.D.I. to sever ties with Rosie. In a dramatic turn, R.U.D.I. makes a choice to protect the Jetsons and abandon S.A.R.A., a decision that sets the stage for a final act of repair and reconciliation. Rosie, determined to reunite her family, enlists help to fix the time machine, and the two families rally to bring the Jetsons home.
The race to the finish line of this grand crossover includes a flurry of pursuits: Sentro’s theft attempt is thwarted, and the evidence it gathered is destroyed. Spacely’s business begins to flourish with a daring Stone Age car concept, even as he cautions Cogswell about copying any element of it. Fred and Barney mend their friendship, and George extends a hand between old colleagues, offering a partnership with Mr. Slate to give the Flintstones’ friends their jobs back. Just as the living device seems broken beyond repair, the car’s power—absorbing the time machine’s “quadra-potents”—enables a return to the Stone Age. With a heartfelt farewell, the Flintstones and the Rubbles bid adieu to the Jetsons, who depart back to their era, leaving behind memories of an extraordinary meeting of two timeless families.
