The Joker, Penguin and Riddler are after an Incan treasure map, but their attempts to steal it are continually thwarted by the teamwork of Batman, Robin and Batgirl; so they plan to break up the Dynamic Duo by making Robin jealous of Batgirl. To top it off, they lure Robin into a trap, where they have hungry crocodiles waiting! I don't know where the plank came from. Some voices: Batman: Olan Soulé Robin: Casey Kasem Batgirl: Jane Webb Narrator, Riddler & Penguin: Ted Knight (2 years BEFORE "Mary Tyler Moore") Joker: according to different sources, either Ted Knight as well, or Larry Storch (who received no on-screen voice credit) TVLand once stated that Olan Soulé voiced Batman on Radio in the 1940's, but this is in dispute. TVLand has been known to make mistakes. We do know that Filmation's voice of Superman in their 1966 cartoons, Bud Collyer, DID voice Superman on Radio in the 40's.