The three segments were:
1) The Curse of Dracula: which depicted the count as a handsome University professor in modern day San Francisco.
2) The Secret Empire: A homage to the Gene Autrey Serial "The Phantom Empire" this story featured a US Marshal who uncovers an underground society of technologically advanced aliens run by the evil Mark (Star Trek) Lenard
3) Stop Susan Williams: international adventure starring Susan Anton as a jet setting reporter who manages to get herself into some deadly situations.
As a child, the Secret Empire was my favourite, so I leave you with an episode.