As the curtain rises, a prophetic scroll appears, reminding us of the fateful release of Alfred Hitchcock's The Birds (1963), where viewers found humor in the idea of birds rebelling against humankind. However, fate had other designs, leading to an astonishing event in 1975 that left no space for laughter. Following this dark premonition, a haunting sequence unfolds: a tomato unexpectedly bursts from a woman's garbage disposal, turning her confusion into sheer horror as it closes in on her.
Once the credits roll, authorities are called to the scene of the unfortunate woman's demise. They discover that the startling red substance covering her body is not blood, but rather the juice of a killer tomato. This gruesome finding sets the stage for a series of horrifying attacks perpetrated by these malicious vegetables, resulting in multiple tragedies, including one man's fatal experience with a particularly lethal tomato juice.
Amid the emerging chaos, the President's press secretary, Jim Richardson, desperately tries to assuage public fears, asserting that no real threat exists. Meanwhile, the Commander-in-Chief assembles a highly specialized task force to combat this peculiar danger. Leading this eclectic team is Mason Dixon, who is joined by an unconventional disguise expert named Sam Smith, capable of taking on the appearances of historical figures such as George Washington, Abraham Lincoln, and even Adolf Hitler. The team also includes scuba diver Greg Colburn, Olympic swimmer Gretta Attenbaum, and soldier Wilbur Finletter, equipped for combat with his parachute.
In a humorous twist, Smith attempts to blend in among the tomatoes at a campfire, but his cover is quickly compromised when he asks about passing the ketchup while enjoying a hotdog. Meanwhile, Colburn and Gretta fan out to different locations, while Finletter remains steadfastly by Mason's side. On a different front, Richardson heads to Mind Makers, an advertising agency recognized for its bizarre marketing campaigns. Here, Ted Swan, the executive, misuses funds on ridiculous ideas, such as a bumper sticker that reads "STP" for "Stop Tomato Program," a lighthearted nod to the "whip inflation now" campaign of the past.
As the situation escalates, a human antagonist emerges, intent on sabotaging Dixon's efforts. A masked assassin attempts to eliminate the leader but fails, adding more layers to the unfolding drama. A senate subcommittee convenes, unveiling a secret pamphlet that prompts Lois Fairchild to dive into her own investigation. While tracking Finletter, she is mistakenly perceived as a spy, leading to a comedic hotel room raid by him in a misguided attempt to dispose of her. Later, in a chase scene, he pursues the assassin who again misses his target, creating more chaos.
With the situation on the West Coast spiraling out of control, the once formidable American forces find themselves in disarray. Amid the turmoil, Dixon stumbles upon a peculiar trail of tomato juice, which piques his interest and leads him toward a risky pursuit. His chase brings him to an apartment where a carefree child is captivated by the radio's melodies. Just as the tomato is about to deliver the final attack, it suddenly escapes through the window, leaving Dixon momentarily disoriented. Peering out into the night, he witnesses the assassin hijacking his vehicle, resulting in a slow-paced car chase that would inspire future comedies. However, Dixon's thrill ride is abruptly halted when he knocks himself unconscious with his own car.
Upon regaining his senses, Dixon finds himself at the mercy of Richardson. While not the one orchestrating the killer tomatoes, Richardson has uncovered their vulnerability and seeks to manipulate this secret to dominate once civilization crumbles. Just as he is about to divulge his plan to Dixon, Finletter makes a dramatic entrance, sword in hand, abruptly halting Richardson's schemes.
As Dixon gathers the remnants of records scattered around him, a pivotal realization strikes him: the killer tomatoes had receded at the sound of "Puberty Love," and it finally clicks for him. He instructs Finletter to assemble the remaining survivors and lead them to the stadium to confront this looming danger.
Wryly, Finletter observes that only the unhinged have managed to survive in what has become a desolate city, gathering a peculiar mix of characters adorning costumes in preparation for the struggle against the relentless tomato onslaught. Cornered and desperate, the tomatoes are subjected to the auditory attack of "Puberty Love" echoing through the stadium's loudspeakers, prompting them to shrink and become susceptible to the crowd's ferocious stomping.
Meanwhile, Fairchild finds herself trapped by a colossal tomato wearing earmuffs, its inability to hear rendering it immune to the music. Dixon intervenes, presenting the giant tomato with the sheet music to "Puberty Love" while declaring his affections for Fairchild through song. As the pandemonium calms, a triumphant carrot emerges from the earth, proclaiming, "All right, you guys. They're gone now."
