Downstream (Land of the Lost)

Inside they meet a crazed man who identifies himself as Jefferson Davis Collie III (Walker Edmiston), a Confederate artilleryman.

The four are ambushed by Sleestak, and Rick puts a red, green, and yellow crystal together, creating a blinding flash that dazes the monsters.

Eventually they find themselves in a swamp, and recognizing the Pylon, realize the river runs in a circle and has led back to their own part of the jungle.

During the filming of a scene where Walker Edmiston fired the cannon, the charge was so strong an actor playing a Sleestak was knocked over.

[1] In 2009, the online review site Premium Hollywood described the episode as "lackluster", but added that it "begins to offer us a peek into how complex this series could become.