Wyrd Sisters | Terry Pratchett

Things like crowns had a troublesome effect on clever folks;
it was best to leave all the reigning to the kind of people whose eyebrows met in the middle.
Three witches gathered on a lonely heath.
A king cruelly murdered, his throne usurped by his ambitious cousin.
A child heir and the crown of the kingdom, both missing.
The omens are not auspicious for the new incumbent, for whom ascending this tainted throne is a more complicated affair than you might imagine, particularly when the blood on your hands just won't wash off and you're facing a future with knives in it...