STRATA goes to the center of the earth and is nearly killed. They uncover cav...
Saul of the Mole Men
Season 1 Episode 18: The Call of the Zither
As explained in the opening theme, there was a mission underground, so STRATA was sent down, only for the crew to die on their way to the center of the earth, leaving Saul Malone, Robot, and Johnny Tambourine all with the mole men.