"The Book of Ephraim," which first appeared as the final poem in James Merrill's Pulitzer-winning volume Divine Comedies (1976), tells the story of how he and his partner David Jackson (JM and DJ as they came to be known) embarked on their experiments with the Ouija board and how they conversed after a fashion with great writers and thinkers of the past, especially in regard to the state of the increasingly imperiled planet Earth. One of the most ambitious long poems in in English in the twentieth century, originally conceived as complete in itself, it was to become the first part of Merrill's epic The Changing Light at Sandover (1982), the multiple prize-winning volume still in print. Merrill's "supreme tribute to the web of the world and the convergence of means and meanings everywhere within it" is introduced and annotated by one of his literary executors, Stephen Yenser, in a volume that will gratify veteran readers and entice new ones.