Progress makes humans take essential things for granted. They become complacent and live an easy life, turning into lazy puppets that are manipulated by those in power. Without realizing it, they are manipulated to enrich the very ones who take advantage of them and squeeze every last breath out of them.

In the early 21st century, humanity lived in a time of technological progress and prosperity, but all that came to an abrupt end. Through their infinite stupidity, humans lost their most valuable treasure: Earth. The planet that had given life to hundreds of generations before them.

The illustrious Dr. Salazar invented a substance they called Engel, a name derived from the nickname they gave him: "the angel of hope." It was a substance that eradicated all the major diseases that had plagued humanity during the 20th and 21st centuries. Broadly speaking, it could be said to be a kind of immune booster that strengthened antibodies, making people immune to any disease. But as a side effect, which was what really skyrocketed its value, it rejuvenated cells, giving its consumers a younger appearance, and fulfilling humanity's ultimate dream: eternal youth.

It was not long after that disaster struck. Earth was invaded by aliens: the Naewat, whose sole desire was to steal our planet and, above all, seize Engel. They were beings of terrifying beauty, and that made humans trust them at first. However, it would not take long for them to show their true intentions. Their intelligence and agility made them perfect killing machines and they gradually began to dominate the weak race: humans.

Their purpose was to steal Engel from the humans, but the humans resisted. Thus began a war that gradually became more bloody. They called it the first interstellar war, but those who experienced it firsthand called it hell.

Dr. Salazar died with what they called the Great Viral Explosion of 2024. A lethal virus was released by the Naewat in their desperation not to be defeated by beings they considered inferior. This wiped out a large part of the population of both sides, thus marking the end of the war and the beginning of a new era for humans and the Naewat, who were forced to coexist to survive.

Although that wasn't such a big deal, because the planet could always be repopulated. The real problem came when they discovered that Earth had been contaminated by the war's waste and became uninhabitable. The few survivors had to live in exile on space stations around Earth, waiting for time to heal the war wounds and...

"But teacher," said a little girl raising her hand suddenly. The teacher frowned at her, as it was the eleventh time she had interrupted her Earth history class. "What if some Engel was left? We could use it to..."

"There is none left. It was adulterated by biological weapons and became toxic."

"But if we went down to Earth and searched... There might be a jar left with a little bit of Engel. With the right formula, it could be reproduced and then..."

"Didn't you just hear that you can't go to Earth?" the teacher replied more irritated.

"But we can use suits like the ones they use to repair the space station. The other day I saw how it was repaired by a mechanic from outside. We wouldn't have to breathe the air of..."

"That's enough, little girl!" the teacher exclaimed furiously. "I'm the teacher here. You just have to listen and learn what you're told. You don't need to think!"

"But..." Tears threatened to well up in the little girl's eyes, but the teacher banged her ruler on the table.

"Enough! Hold out your hands..."

"No!" the little girl hid them behind her back in fear.

"This will teach you to stop questioning what we tell you. Hold out your hands!"

With fear shaking her trembling hands, the little girl extended her hands on the table and the teacher hit her knuckles. With a whimper, she pulled her hands away and brought them to her mouth, looking at the teacher with eyes filled with tears and wishing that her anger had subsided with just one blow, but it was not so.

"Hold out your hands again, girl," she growled menacingly. "And every time you pull them away, you'll get an extra hit. Instead of five, I'll give you six."

The little girl began to sob and extended her hands again. Another blow made her stifle a scream, but this time she didn't move them. She rested her forehead on her desk and waited for the next blow. Another. Another one. Each one more painful than the last. By the time the teacher had finished disciplining the little girl, her knuckles were bloodied.

"Go to the infirmary to get them treated," the teacher said as she wiped the blood off the ruler with a cloth. Then she looked at the rest of the class. "And I hope this serves as a lesson to everyone. To survive, humanity doesn't need people who think. It only needs obedient people who do what they're told. Do you understand? That's the only way we can one day live on Earth again."

"Yes, teacher," all the children repeated in unison.