Now that Halloween is here, we will be invited to frighten ourselves with scary masks and terrifying movies. Why? How is it that fear – the primitive defense mechanism that warns us to fight or flee when faced with danger – can be pleasurable? And yet that paradoxical wish to be frightened is as ancient as narrative art itself. From Grendel lumbering murderously out of the darkness in the eighth century poem "Beowulf," through the tales recorded by the Grimms and down to our own age, storytellers have catered to our desire to be made fearful.