On the planet ZTEOG an evil zteogian had amassed a large army to overthrow the planetary government. His plot failed, and as a punishment he was exiled to a boring and senseless planet, the Earth. To further guard against escape, he was left in the most idiotic and depressing region, the moorland of England.
Hofcheliffclo (anglicized as Heathcliff) decided to escape from this pitiful planet and to get revenge on his people. To accomplish this he had to first conquer Earth. Using advanced medical technologies and weird psychic and telekinetic powers, he implanted himself in the body of a small gypsy boy. He used his psychic powers to force Earnshaw to take pity on him and take him home. There he was to bide his time and slowly take over the planet.
The zteogian body produces a weird radiation that causes humans to become evil, sick, insane, and to die a slow painful death. Heathcliff's presence at Wuthering Heights caused it to become evil, and all of the people there were affected. He decided to grow up as a human child, so he could better understand human psychology and make conquering and subjugating the human race easier. In the process of regenerating himself, he accidently dosed Catherine with a large burst of radiation, mutating her into an evil creature like himself.
Heathcliff had soon fallen in love with this new, evil Catherine. By being in human form he had become vulnerable to the weirdest human emotion, love. Unable to understand it, but bound by it, he blindly loved Catherine. He had recklessly thrown away his plans so he could be near her. Then one day he made a terrible mistake; he revealed to Catherine who he really was. She was scared; their love continued but it could never be the same. She married Edgar Linton. Enraged, Heathcliff left to re-establish his plans. He took control of another body and became Napoleon. This explains why Nelly thought Heathcliff had joined the military. His human body soon betrayed him, and his love for Catherine drew him back. When he had returned, Catherine was crazy. Soonafter she had died. In a fit of sorrow, rage, and vengeance, he decided to conquer England slowly, first by getting Thrushcross Grange. He succeeded in this, but his life was empty without Catherine. He faked his death and returned to Europe to continue his exploits as Napoleon. After a period of absence, his evil radiation faded. Soon Hareton and the young Catherine were able to spend a happy normal life, and they all were happy.
Meanwhile Napoleon almost managed to conquer Europe by 1812. Most of Europe was helpless to stop him, and he spread evil wherever he went. Then he decided to conquer England. At the battle of Waterloo he was winning, until he saw Wellington. Wellington was Catherine's third cousin (and also fourth, by inter-marrying) and the resemblance was striking and Napoleon/Heathcliff went to pieces, and lost the battle. He decided to give up for a while and faked his death again on the island of Saint Helena in 1821.
Determined to escape this planet, Heathcliff managed to artificially stimulate technology. He was driving the human race to space, so he could escape. The time was right in 1933, and he again took human form as Adolf Hitler. He again spread evil, and again almost succeeded in conquering the world. Again his major downfall was the failure in conquering England, because he did not want to go there and be reminded of Catherine. Finally in 1945 the German V-2 rocket technology was sufficient for him to build a ship and escape, leaving the Earth to recover from World War II and a lot of technology they did not know what to do with.
The book Wuthering Heights itself was written as a warning. It was written by the good zteogians through Emily Brontë to warn us about Heathcliff/Napoleon/Hitler. The book has subliminal messages on how to stop him and where to contact the zteogians for help. Unfortunately the writing was too subtle, and the zteogian understanding of human psychology was lacking. Instead the subliminal message affected females, making them like the character of Heathcliff. It affects males by firing centers in the boredom and hatred areas of their brains. It also has the affect of taking usually smart English teachers and forcing students to read the book, which is useless now that Heathcliff is gone. To any extent this is what the book is really about.