Outside the next morning (7:45 am on a Saturday) from the upstairs window of his office, they notice that the town is unusually busy - the streets are filled with pedestrians and Santa Mira police. Although everything appears normal, it is not. They watch as the invasion of 'body snatchers' proceeds. They see trucks arriving, loaded with freshly harvested seed pods, to be divided among friends and relatives in other towns, to spread the invasion in other communities. The townsfolk walk about taking directions and carrying the pods without question. Some put the pods in the trunks of their cars. Miles senses the deadly contagion spreading unchecked in the seemingly normal community, neighboring towns and cities: "It's a malignant disease spreading through the whole country."

Just then, Miles hears Jack's voice in the hall, accompanied by Dr. Kaufman. Obviously, both have been taken over by podded aliens, and Miles and Becky are among the few unaffected by transplant absorption:

We can't let you go. You're dangerous to us. Don't fight it, Miles, it's no use. Sooner or later, you'll have to go to sleep.

They place two fresh pods in Miles' waiting room next to them, to grow duplicates when they fall asleep. The complacent Dr. Kaufman explains the alluring benefits and advantages to them of symbiosis (of being "reborn into an untroubled world" without an awareness of separateness):

Less than a month ago, Santa Mira was like any other town. People with nothing but problems. Then, out of the sky came a solution. Seeds drifting through space for years took root in a farmer's field. From the seeds came pods which had the power to reproduce themselves in the exact likeness of any form of life...Your new bodies are growing in there. They're taking you over cell for cell, atom for atom. There is no pain. Suddenly, while you're asleep, they'll absorb your minds, your memories and you're reborn into an untroubled world...Tomorrow you'll be one of us...There's no need for love...Love. Desire. Ambition. Faith. Without them, life is so simple, believe me.

Determined to escape, wanting no part of being half-alive, Miles vows to get away, but realizes that there is little hope. Becky cries in Miles' arms that she wants to save them from a loveless future:

I want to love and be loved. I want your children. I don't want a world without love or grief or beauty. I'd rather die.

After knocking out their captors with hypodermics filled with drugs, they successfully make their way to the street, and try to imitate the emotionless, sleepy nature of the other "pod people" with a quiet demeanor. Miles suggests they pretend: "Keep your eyes a little wide and blank. Show no interest or excitement." However, they are betrayed when Becky screams as a dog is nearly run over by a truck. Now the whole town is after them.

In the gripping and frightening finale, Miles and Becky flee from the town's space pods to try to elude the enemy and get help, while struggling to stay awake and remain human. As the last two humans (non pod-people) left, they escape into a hilly wooded area and find refuge in an old abandoned mine, as scores of townspeople follow them. Weary and desperately exhausted, they are again compelled to hide in a constricted place - under floorboards in a pit, located in the dark, deserted cave or tunnel that is perilously close to their pursuers. Miles leaves the faint Becky when the aliens depart to discover the source of beautiful singing or music that they hear. [The music is not a sign of humanity - it turns out to be from a truck radio owned by pod people at a pod farm, who are loading more pods.] Becky can't keep her eyes open any longer. She falls asleep briefly. When he returns to the mine, he finds her lying slumped over and prostrate with fatigue. He tries to force her to go on, starts to carry her, but falls in a puddle at the mine entrance.

And then, in the film's most memorable and frightening moment, he takes her in his arms to kiss her, and then draws away from her unresponsive lips. In a tight closeup shot of her face, he looks into the blank, dark, expressionless and staring eyes of his fiancée, realizing with a look of utter fright that she is now one of "them" - her body has been invaded and snatched. He knows instantly that this is not Becky but a treacherous imposter and victim. His sweetheart of a moment ago now screams to the pod-people searchers:

He's in here. He's in here. Get him. Get him.

Horrified that he is now completely alone, Miles helplessly rushes in panic from the tunnel. He speaks, in voice-over:

I've been afraid a lot of times in my life but I didn't know the real meaning of fear until, until I had kissed Becky. A moment's sleep, and the girl I loved was an inhuman enemy bent on my destruction. That moment's sleep was death to Becky's soul just as it had been for Jack and Teddy and Dan Kauffman and all the rest. Their bodies were now hosts harboring an alien form of life, a cosmic form which, to survive, must take over every human man. So I ran, I ran. I ran as little Jimmy Grimaldi had run the other day. My only hope was to get away from Santa Mira, to get to the highway to warn the others of what was happening.

He clambers up the hills to a busy highway, where he attempts to flag down cars, and convince passing drivers (concealed in their pod-like, mechanical cars - a symbol of capitalistic society) to help him and believe his story. Crazed with fear, he rushes into the onrushing traffic, nervously shouting and crying words of warning to the unheeding cars and unconvinced drivers. He flings himself onto the windshield of one of the automobiles, but he is ignored. Realizing Miles is being met with anger and rejection, a lone and doomed figure unable to save his world from invasion, one of the pod people decides to let him go:

Wait. Let him go. They'll never believe him.

A disheveled Miles pleads with the drivers for help:

Help! Wait! Stop. Stop and listen to me!...These people who're coming after me are not human. Listen to me! We're in danger!... They're after all of us! All of us!....Listen to me! There isn't a human being left in Santa Mira!... Stop! Pull over to the side of the road! I need your help! Something terrible's happened!...

In frenzied desperation, Miles climbs on the back of a passing truck with the names of cities on it, horrified to find it loaded with pods to be distributed and spread throughout the nation. He drops off, jumping back on the highway - feeling completely helpless. As a crazed prophet of doom, he looks directly into the camera, desperately trying to warn others and the audience:

Look, you fools. You're in danger. Can't you see? They're after you. They're after all of us. Our wives, our children, everyone. They're here already. YOU'RE NEXT!

END OF ORIGINAL FILM -

ADDITIONAL EPILOGUE:

This blunt scene with a despairing ending dissolves back to the start of the story for an epilogue, where we originally found a distraught and raving mad Miles relating his fantastic nightmarish tale in a hospital. The doctors comment that he is a lunatic and as "mad as a March hare." As the doctors leave the office, another accident victim from a wreck is brought in by ambulance. One of the doctors explains how there was a collision between a Greyhound bus and a truck, and how the truck driver had to be dug out from under a peculiar pile of "great big seed pods" from a truck coming out of Santa Mira.

Verifying and confirming Miles' story, the police start to take control of the invading aliens by blocking highways, and the FBI and law enforcement agencies are notified of the emergency. An all-points alarm is sounded and Miles is finally vindicated and relieved that someone has finally believed him.