Lora faces a dramatic final battle between the Ancient Heart of Mars, which holds her family prisoner, a repository of all the life force of the planet, and the Hybrids of the City Inside.

Both claim they are on the side of the humans and the Ancients have the power to restore their starships to working order, if they can only learn the secret of star-flight.

Reunited with her family but caught in the middle of the conflict, will Lora decide to stay on Mars or leave forever? And what part has their ancient robot, Toaster, still to play in the fate of the red planet?