Just as crime boss Turk Jackson is about to turn himself over to the authorities, under Clark Kent's watchful eye, wacky inventor Professor Twiddle shows up with his latest invention: a time machine. No one believes it can really travel in time, so he demonstrates by hurtling them all — Turk, Clark, Lois, Jimmy and Perry — back 50,000 years. However, he failed to think of one thing: how to get them back.
Turk, however, realizes that this is his get-out-of-jail-free card. Being the only one in possession of a gun, he starts bossing everybody around, including a couple of cavepeople they meet, and he hides the time machine. After he inadvertantly causes a cave-in, however, Superman shows up, hand waving about how somehow his superpowers enabled him to follow them back through time. He locates the metal that Twiddle needs to adapt the time machine to get them back, and eventually Turk reveals the machine's location once he discovers diamonds in the cave, with which he thinks he can buy his freedom. Once they return to the present, however, the stones turn out to be quartz.
This episode contains examples of:
- Abhorrent Admirer: Lona the cavewoman takes an unwanted interest in Perry White.
- Did Not Think This Through: Prof. Twiddle takes the cake and all the ice cream on this one: he sends everybody 50,000 years into the past without a plan to get them back.
- Fanservice: Noel Neill takes a break from her normally sensible clothes and puts on a leg-baring cavegirl outfit.
- God Guise: After the cavepeople glimpse Superman and are clearly in awe of his powers, Turk paints an S on his hide and takes a This Is My Boomstick approach to convincing them he's Superman's equal.
- Hair-Trigger Avalanche: When Turk fires his gun inside the cave, it sets off a shower of rocks that block the entrance.
- Haven't You Seen X Before?: At the end, when our gang gets into the Daily Planet elevator still wearing their prehistoric skins, they understandably get some questioning looks. Perry White just says, "Well, what's the trouble? Didn't you ever see a caveman before?"
- Knockout Gas: After the cave-in traps the whole crew, Clark decides he has no choice but to reveal that he's Superman... but just as he's taking off his glasses, coal gas fumes fill the cave and knock out everyone except him.
- Misplaced Wildlife: Well, misplaced human wildlife: there shouldn't be any people in North America in 50,000 B.C.
- No Man Should Have This Power: Twiddle vows to destroy the time machine once they get back to the 20th century.
- This Is My Boomstick: Turk tries to convince the locals to follow him by using his gun and his lighter.
- Wizard Duel: Once Superman breaks into the above scene, it turns into this: Turk can make fire with his lighter, but Superman can do it with his eyes.
- Worthless Yellow Rocks: Played with. Turk finds some diamonds, which the primitive folks attach no value to. But once he gets back to the present, it turns out they really are worthless, because they're actually quartz.
