find any explanation nor any sign of life,

Meanwhile, while no living being has been sighted, menacing strange sounds and controlled wisps of fog manifest themselves. Also those crew members who sleep alone are suddenly -found attacking their comrades evidence of an unseen and dangerous presence with strange powers over minds of men.

The remaining members of the expedition now start to die or vanish one by one until Captain Mark corners and captures one of the supposedly dead crew members to learn that it really is an inhabitant of Aura - a mind without a body which has taken over the body of the crewman, as have his fellow Aurans. He now solves the diabolical mystery of the planet
- it is inhabited by advanced minds who have been seeking bodies to escape from their home plus a space ship to travel to another world!

The surviving crew of the Argos then foil the Aurans plot to disable their ship and take over the crippled Galliot. Captain Mark and Sanva are the sole Survivors as the Argos is reactivated and they escape to try to fly back to their home planet.