Defend the portals. Defend the universe.
Sent back to Earth, Christy bides her time plotting to go back to the Empty World. She has the means; she just needs to round up as many friends as she can and convince them to go with her. All is not right in the Empty World, and Doug and Mike may not be able to defend the pyramid by themselves.
When the Ancients manage to steal the crystal protecting the massive power source contained inside the pyramid, it’s a race against time. Christy and her friends must track down and restore the crystal, or the released black hole won’t just destroy the Empty World…the whole universe is in danger!