Lost in Space (1965)

S2E13 The Wreck of the Robot

During an outdoor game, Will and Smith's ball unexpectedly explodes, revealing that it's transformed into gold. As the smoke dissipates, the ball rolls into a nearby cave, home to three aliens. The aliens demand the crew's robot, but when Will declines to hand it over, Smith agrees. Now, the team must figure out a way to reclaim their robot from the aliens.