Second Earth's Beginning: The Moons' Alignment

The Earth is in ruins and the remaining population has to find a new planet to call home. In desperation the remaining population are loaded up into several special spaceships and launched out in hopes to find their new home planet in attempts to save the human race. Upon arrival of their new planet, they come across a new species very similar to them. This species however has reptilian features, each one different from the next. An organization is formed to travel and discover life and new areas on this planet. Terry is sent on a journey with one of the head leaders, Sonia Marie, in attempts to find this cave that she had discovered on a previous journey. The cave was being guarded something, possibly a dragon, and she was unable to get close. However, the opening to the cave is only visible when the three moons are in perfect alignment with each other, an occasion that happens only once a month, then the cave disappears again at sunrise. The two need to find out what is inside, and what it is guarding and why.