With a friendly alien spaceship called Egg always close by, Spartan, his three friends, and his dog, Grimm, continue their adventures traveling the Universe. In Book 2, The Reefs of Mindoro Island, the team of explorers goes to the South China Sea to visit the beautiful isle of Mindoro. It is the seventh-largest island in the Philippine archipelago where thousands of miles of precious coral reefs, abundant with wildlife, are in danger. Spartan and his friends face a challenging mission; to stop some reckless and avaricious fishermen from blowing up the very fragile coral reefs with explosives. They befriend a brave young girl from the traditional Iraya Mangyan tribe, and are presented with an obstacle: in order to save paradise, they must take a huge risk.