Wyrd Sisters is the second Discworld novel to star Granny Weatherwax, and it's even funnier than the five before it. This book introduces Granny's "coven", consisting of Nanny Ogg and Magrat Garlick, who appear in future titles, and opens with the classic lines:
"When shall we three meet again?"
"Well, I can make next Tuesday".
This gives a good indication on the flippant way that witchcraft is handled throughout the book, and a lot of the humour comes from Magrat taking rituals a lot more seriously than her companions, despite being the youngest. The conversations between the three witches are Discworld series highlights for me.
The main plot of this story parodies Shakespeare, mostly Macbeth and Hamlet (it's not hard to see why they increased the number of central witches to three in this book), and starts off with the ghost of a murdered King trying to avenge his death when his killers take over the throne, and meanwhile the rightful heir to the throne is adopted by dwarves, who also happen to be actors. The witches eventually get involved in the whole effort to get the correct person back to the throne.
The plot isn't exactly complicated, but the book is enjoyable to read for the constant references to Shakespeare, and two hilarious moments involving characters watching plays, which include Granny Weatherwax not realising that it is all acting, and the three witches getting mistaken for the actors who are playing the witches.
I love the way that Discworld never revolves around a single character, and this is the first book in the series to not include Unseen University (or wizards) at all, although as ever Death is present to make cameo appearances. The books about the Discworld witches are among my favourites in the Discworld series.
Next book: I, Partridge: We Need to Talk About Alan by Alan Partridge