Lost Race Of Mars

Are the Old Martians really a lost race--just withered mummies lying in dark caves? Or are they still alive--somewhere on the red planet? Sally and Jim must find out. They must help their father discover if the Old Martians still exist. His life work as a scientist is at stake! But it's not easy. They are only visitors to the Mars colony in this year 2017. And no one really wants them there.