Count Magpyr and family are invited to the naming of Magrat and King Verence's daughter, to be conducted by the Omnian priest, Mightily Oats. For some reason, the Magpyrs are not keen to go home to Überwald, and, once again, the witches, Granny Weatherwax, Nanny Ogg and Agnes Nitt (aka Perdita) have to save the mountain realm of Lancre.  The Magpyr family have made themselves much more formidable enemies by building up tolerance to the normal methods used to defeat vampires, such as garlic, bright light, and religious symbols. They exert a hypnotic charm over normal people which prevents them from realising that the vampires are taking over Lancre. Only the youngest witch, Agnes, and the Omnian priest, Mightily Oats, seem able to resist this charm, due to their dual personalities. The Magpyr son, Vlad, is attracted to Agnes because she is able to resist him.  There is an Igor who is the servant of the Magpyrs. He is a traditionalist who spends his spare time breeding and distributing spiders for the dark corners of the castle. The Magpyr's are very rude to him, and eventually he rebels.  The vampires identify Granny Weatherwax as one of their more significant foes, and decide to deal with the problem by converting her to one of them.  Other characters from earlier Discworld books who appear in this novel are Death, Hodgesaargh and Nanny Ogg's cat, Greebo.  It should also be noted that this novel bears significant plot similarities to Lords and Ladies, like a celebration (Magrat and Verence's wedding in Lords and Ladies, their daughter's christening in Carpe Jugulum), the intrusion of outsiders with mind-affecting abilities (elves in Lords and Ladies, vampires in Carpe Jugulum), and part of the solution to the conflict being a forgotten member of the outsider faction (the King of the elves in Lords and Ladies, the old Count in Carpe Jugulum).

An interesting novel about people's inner selves and the interesting lives they can lead. It's also about Vampires trying to be people and learning how to be really good at being bad. For once Granny sits out much of this story (in a cave to be exact) and it's up to Nanny, Magrat and Agnes to try and sort of save the day a bit, Nanny thinks they can achieve this through sex and while it's an interesting plan it's quickly dismissed by the younger women. Mightily Oats is an interesting character, possibly the only person to be as good at his job as Granny is at headology. The Nac Mac Feegle are an interesting addition too, possibly the fevered production of a drunken orgy above a Glaswegian ale house next to a Rod Steward concert being hosted by the Big Yin himself, they're both funyy and very serious at the same time. Lastly there's Igor, more the sum of other people's parts than most, he's never the less a traditionalist and knows how to get good cobwebs made fast. Let's hope he (or at least parts of him) will turn up again...