Unless I missed it, there's not a single reference to Diamond Head in this Hawaii-set soap opera. Nevertheless, the meaningless title is not the most perplexing thing about the film. What's astounding is how seriously Charlton Heston, Yvette Mimieux, James Darren & George Chakiris take this melodrama. Heston is Richard "King" Howland, a modern day ruler of a plantation where nothing transpires without his input. Mimieux is his extraordinarily younger sister, bent on marrying islander Darren. A lot of lurid nonsense ensues as Heston's hypocrisy is revealed. There's no action, some fairly lousy acting and some rather dull direction by Guy Green. Heston says "damn" a lot, Mimieux gets drunk a lot and France Nuyen (as Heston's kept woman) espouses a lot of common sense advice to virtually everyone. Frankly, the film is so boring, an eruption by ANY volcano would have been most welcome.