Waking Mars

Waking Mars is the third book in the series after The Medallion and The Rescue. In Waking Mars, the aliens, whose planet had accidently became part of the solar system, saw the potential in vitalizing Mars to a livable level. They were lucky to encounter another alien race that helped them to achieve that goal. Meanwhile, on Earth, a nuclear war had erupted and led the way for the extinction of life.