The saga, secrets and mysteries of the first family to colonize the hostile Red Planet. After arriving on Mars, the young Emily, daughter of the commander of the first colony, while working with her father on daily tasks, decides to explore the surroundings of their base. But strange phenomena begin to occur and, one day, she discovers an opening that leads to a cave where she encounters elements that seem to disturb her mind. She visits the cave several times but by an accident of fate she discovers that there is an underground city inhabited by an unknown native Martian race. In the underground she meets the Martian civilization and the young king of this mysterious people called Marcius. The earthling girl and the Martian ruler become friends and their friendship deepens, with the two of them meeting secretly every night, and they soon discover that despite their differences they have a very intense bond, but dangerous intrigues threaten to destabilize the underground kingdom. And there's a reason for that: a second Earth-bound spaceship arrives from the red planet bringing new threats. Emily and Marcius must fight against their own kind and consolidate a fragile alliance between humans and Martians if they are to protect their shared future. Both the young human and the ancient Martian civilization soon find themselves on the brink of war and destruction. In a race against time, they must overcome age-old mistrusts and cement a fragile alliance between species, or watch what they hold most dear be wiped out forever.