This tribe of hunters must use whatever they can find to nourish themselves and survive. Luckily, two of their children stumble across a pond full of fish after the ice melts, giving them plenty more to eat.

Food is scarce, too many men, not enough game to kill. What are they to do? The explorers setting foot on the Americas are having a tough time.

This new episode of "Il était une fois..." covers Cortés and the Aztecs. The story starts in 1519, when Ferdinand Magellan attempts to circumnavigate the earth. His ship makes it as far as Brazil.

The Maestro recounts the events just before Ferdinand Magellan's untimely death in 1521, only a year after he discovered the passage that would allow him to circumnavigate the globe.

The Aztecs are apprehensive about the arrival of the white men. It is a bad omen. Spanish conqueror Cortés is appointed Captain and will be heading toward new territories.

November 18, 1518... Cortés, the ambitious adventurer, sets out to discover and conquer the unknown empire of Mexico at daybreak before Velasquez has a chance to stop him.

Cortés is negotiating with the friendly natives of Mexico with the help of his interpreter, who had been shipwrecked in a previous expedition and speaks Mayan. They are offered a young woman slave, Malintzin, who speaks Mayan and Aztec.

Cortés exchanges gifts with the Aztec Emperor, Montezuma. An excellent diplomatic move on both sides!

Tension is building between the Aztecs and the Spaniards, not to mention within Cortés's own ranks. Despite this, the conquistador rallies his troops to conquer Mexico.

Cortés sets out to conquer Mexico with his four hundred men, sixteen horses, and seven cannons. He is joined later by native forces, the Totonac warriors.

Have you ever wondered what a blood platelet actually does? Find out as the Once Upon a Time... series tackles biology.

Although antibodies mainly protect against bacteria, viruses, and other foreign substances, sometimes they can also attack your own blood cells! But this cartoon explains why you don't have to worry too much about that happening.

When the young platelets in this cartoon decide to have some fun and create a sort of "platelet pyramid" out of themselves, their older friend warns them that they could be causing a blood clot!

Watch the blood platelets in action in this fun cartoon. Moral of the story? Always listen to your mother.

The platelets vanquish the bacteria in the final installment of this animated series on blood. Who knew that a simple cut could be so epic?