We return to Aldebaran, the planet where the first human colony in the solar system was founded. Mark and Kim, teenagers whose village was annihilated, have met a woman named Alexia during their escape. She is a biologist and a friend of Driss, the man who knows a lot about the catastrophe. Alexia shares Driss's secrets. The government is very interested in her and sends soldiers to pursue her. While trying to help her, Mark is arrested and languishes in prison for 3 years. It's the mysterious Mr. Pad, an odd character Mark has already met, who helps him escape from prison.