"Double, double toil and trouble; Fire burn and caldron bubble. Fillet of a fenny snake, In the caldron boil and bake; Eye of newt and toe of frog, Wool of bat and tongue of dog, Adder's fork and blind-worm's sting, Lizard's leg and howlet's wing, For a charm of powerful trouble, Like a hell-broth boil and bubble. ... Double, double toil and trouble; Fire burn and caldron bubble. Cool it with a baboon's blood, Then the charm is firm and good." [From Shakespeare's Macbeth.] All Hallow's Eve near ...