A giant robot goes out of control and attacks people, but its creators try to prevent the authorities from destroying it. They encounter a group of alien invaders who were not prepared to face a robot and are driven away, moments before the police arrive and blast Mechano to bits.
Alien ships appear over Earth, causing panic. After a failed military strike, the world's leaders disarm at the advice of an old astronomer, who had actually faked the ships to create unity.
A disgruntled janitor uses a time machine to travel to King Arthur's time to pose as a sorcerer using technology. None of it works independently, and he is forced to mop up the great hall.
The world president insists on missions to find a hidden planet, always leading to failure. When his daughter is killed aboard the latest rocket, the attempts to reach "Earth" are abandoned.
When an alien crash lands on Earth, he is met with violence by men, but is befriended and helped to return to his ship by a dog. From orbit he thinks about destroying the planet but realizes that would kill the dogs too and refrains from his plan.
A dictator conquers an alien world full of unresisting people. He quickly finds that they are already slaves of the sentient plants, which now also control him through their spores.