The trains having landed on the Wandering Planet's surface to rescue the two Maetels, Redril and Testuro confront two extremely alien-looking creatures who refer to themselves as "humans". When the aliens confirm to their satisfaction that Tetsuro, Redril, the two Maetels and the two Conductors are flesh-and-blood and not mechanized, they are permitted to return to the trains. As they prepare to lift off, the Conductors are seized by a pair of mechanical creatures with a shape resembling that of the two "humans" they encountered before. They demand that the two boys surrender their passes and allow them to take their place on the train. (thetvdb.com)