Moving to Chincoteague has been hard for Alison Grossbard and her younger brother Arnold. When Dad lost his job as a reporter in Baltimore after speaking out against the High Ones—big, blue starfish from space that now rule the Earth—he was lucky to get a job at the local fusion plant. Sure, the High Ones brought wonderful technology—tri-vees and interplanetary travel and nuclear fusion—but the High Ones and their human flunkeys punish anyone who questions their rule, including teenagers like Alison and Arnold.

With the help of Gloria, an alien who can bridge dimensions, and Jo, a girl from an alternate universe with real, live dragons, Arnold and Alison decide to fight. But the High Ones aren't the only enemies. Can Arnold and Alison become Heroes of Earth without sacrificing themselves?