undersea kingdom must rank at the very bottom of the cliffhanger serial . why it so bad . well it be show on consecutive night on bbc2 many year ago and watch every episode less than 24 hour apart it become patently obvious that the audience be be cheat . every single cliffhanger be re edit at the reprise and the bad example be an episode that finish with a tank that have the hero strap to it front smashing through a wooden gate of a fort and a loud crash and splinter everywhere there be no way our hero could possibly have survive the impact then the follow episode show ( . possible spoiler . ) the people inside the fort open the gate before the tank crash through . this go beyond cheat and remain the bad resolution to a cliffhanger ever . so give this rubbish a miss unless you ` re interested in see lon chaney jr in a cameo in the first episode or you ` re want to laugh at some bizarre robot who be obviously men with a water boiler over their head .