Carpe Jugulum

Count Magpyr and family, vampires from Überwald, are invited to the naming of Magrat and King Verence's daughter, to be conducted by the Omnian priest, the Quite Reverend Mightily-Praiseworthy-Are-Ye-Who-Exalteth-Om 'Mightily' Oats, a recent graduate from theological college.

During the party after the ceremony, Verence tells Nanny Ogg and Agnes Nitt that the Count has informed him that the Magpyr family intend to move into Lancre Castle and take over.

Meanwhile, Granny Weatherwax, feeling slighted by not receiving an invitation to the ceremony, has left her cottage empty and seems to be working towards a life in a cave, almost like a hermit.

After they have left the hypnotic influence of the Vampires, Agnes, Nanny Ogg and Magrat attempt to convince her to help them save Lancre, but apparently without success, even after Granny is informed that her gilt-edged invitation was stolen by a magpie.

Surprisingly (for the Magpyr family, at least), the old-fashioned ways to defeat vampires that they thought themselves protected against start to work again (with conditioning against religious symbols resulting in the recognition of such in any random pattern).

All is revealed when Granny (who has "helped" Mightily Oats to Überwald by being carried by him), tells them that — far from turning her into a Vampire — they have, instead, been 'Weatherwaxed'; she had magically "Borrowed" her own blood, which they drank, allowing her past their mental defences.