In Ghost in the Machine and The Eye, its revealed that the Espheni are building a new power source for their technology that will allow them to control humanity forever and to defend themselves against their Great Enemy. The Volm seek out this new power source on Earth, unaware that its actually located on the Moon, resulting in them having no luck in their searches.
Eventually Tom and Hal Mason notice that a shot-down Beamer is reacting to moonlight and powering up while green flashes can be seen from a location on the light side of the Moon. After Cochise examines it, he realizes that the Moon is the location of the Espheni power core he and his men have been seeking. The 2nd Mass realize that the Espheni would only put their power core on the Moon so it could cover the whole planet and power all their technology here. Realizing that destroying it would take out all Espheni technology on Earth, Tom begins to organize a mission to the Moon to destroy the power core using the shot-down Beamer.(A Thing With Feathers) (Til Death Do Us Part)
Eventually, an attack is launched against the power core using the Beamer. Using the Beamer's autopilot to lock onto the Espheni Moonbase's homing beacon, Tom and his half-Espheni daughter Lexi fly to the power core. Along the way, a life support problem destroys their bomb and Scorch captures their ship in a bigger one of his own as they near the Moon. After Tom kills Scorch, he decides to use Scorch's ship as the bomb instead, but Lexi discovers that Scorch destroyed his ship's autopilot system before he died. Finding that she can still fly the ship manually, Lexi decides to fly it herself into the power core, sending Tom back to Earth in their original Beamer. Tom comes under attack by a Beamer squadron summoned by Scorch before he died, but Volm reinforcements in the form of Waschak-cha'ab and his battleship destroy the squadron and save Tom. Lexi ends up flying Scorch's ship directly into the power core in a suicide run, destroying it in a massive explosion that is visible on the Moon from the Earth. The destruction of the power core takes down all the Espheni technology as was hoped and part of the Moon is turned green for a time from the power core's destruction.