Pyramids by Terry Pratchett

This book is a really entertaining entry in the Discworld series. Although there's a section set in Ankh-Morph, most of the book is set in a kingdom that seems suspiciously like Ancient Egypt, positioned, for good measure, between Greece and Troy. The heir apparent, Teppic, has been in Ankh-Morph learning to be an assassin, but comes home when he learns of his father's death. There he must confront an insane (and functionally immortal) high priest who orders the construction of a pyramid that will alter the fabric of space and time. With the help of the dead pharaohs, a recalcitrant camel, and his (unbeknownst to him) half-sister Ptraci, Teppic must under the mad priest's work before it's too late. This book is funny and smart, and a great addition to the series.