The Pale Horse by Agatha Christie

This book is out of the ordinary for a Christie work, and one of her better efforts. Christie is not great literature, but there is more depth to her better books than she is usually given credit for, and this book is a case in particular.

Besides being a decent mystery, the book is also a meditation on the nature of evil. Is evil flashy and flamboyant, or small and mean, or perhaps both? Does supernatural evil really exist in the universe? Is the occult genuinely evil and is it effective? These and other similar questions are theme of the work.