Wyrd Sisters by Terry Pratchett

In this book Granny Weatherwax returns to see to affairs of succession in the kingdom of Lancre after its king is murdered in cold blood. This book was funnier than previous Discworld novels, although I might attribute that to the fact that much of its parody is based on Shakespeare (with whom I'm familiar enough to find it hilarious). Altogether one of the better Discworld novels so far.