Bat scientist Dr Beck (Stewart Moss) and his wife Cathy (Marianne McAndrew) are on their honeymoon. Part of this includes going down into some caves, Dr Beck ends up being bitten by a strange bat. This causes him to transform into a giant vampire bat at night!
Beck-bat has a taste for human blood of course but eventually manages to escape and return to the rest of the bats. Cathy meanwhile has also been infected by the bats and kills the local police man with the help of an aerial bombardment of bat poo...
Not a good film by any means, it is fairly entertaining from a cheese point of view but lacks much in the way of originality or quality and is padded out too much with irrelevance. The theme song is pretty good though.