George Herbert, C. Thomas Howell explains that after years of scanning the skies for signs of life beyond Earth, humanity never anticipated that aliens could be undone by something as tiny as the bacteria in human blood they consumed, a flaw that helps plunge civilization into anarchy. Two years pass, and a town of silent refugees forms, its streets quietly watched over by people like Shackleford and Sissy. The peace is shattered when three Tripods descend into the city, replacing the walkers of the earlier invasion with taller, more menacing machines. A deadly Heat-Ray devastates the area, and in the chaos Shackleford seizes a sample from Sissy and injects himself, hoping to unlock a way to fight back.
In Washington, the country remains fragile and unsettled. Herbert notes a familiar radio disturbance—the same signal that preceded the first invasion—and warns Major Kramer Fred Griffith and a team of scientists that the aliens are attempting to forge a wormhole between Earth and Mars for another assault. A squadron of fighter jets, built for deep-space flight, launches a bold raid on Mars. When Herbert returns home to find his son Alex seized by a Tripod, the world suddenly turns intimate and perilous. He flees to an abandoned city and discovers Pete Christopher Reid sprinting from a pursuing machine. George throws himself between the machine and his son, a heroic act that lands him inside the vast alien craft alongside Pete. They escape with Sissy, while the Martians begin a second invasion, striking London and Paris as Major Kramer leads the jet fleet in pursuit of the alien mothership back to Mars.
Back in the shattered town, George, Pete, and Sissy find themselves back at the place where the nightmare began. Shackleford reveals a chilling truth: the town was constructed by the Tripods as a staging ground for humans captured to live on Mars. He and Sissy are dying from a virus lethal to the invaders, a diagnosis that spurs him to urge George to act. With nothing left to lose, Shackleford convinces George to inject himself with the infected blood, a risky gambit intended to turn the tide. The trio are captured once more and pulled aboard the mothership, where they discover Alex in a cocoon, the boy symbolizing the human cost of the invasion.
Inside this colossal labyrinth, George injects the infected blood into a pod containing a brain that is telepathically linked to all the Tripods. The act triggers a system-wide disruption, effectively stalling the invasion as the brain-bound network falters. George, Pete, and Alex seize the chance to escape just as the mothership begins to crumble and explode. George emerges from the ordeal bearing the infection’s lingering threat but alive; the planet erupts into a cautious celebration as radios crackle with static, hinting at a possible third wave of attack. The film closes on a moment of tense, subdued silence, leaving the future uncertain yet filled with a stubborn, fragile hope.
