The cover of The Changing Light at Sandover shows the ballroom of James Merrill's childhood home in the 1930s

The Changing Light At Sandover is a 560-page poem by James Merrill (1926-1995). Sometimes referred to as a postmodern apocalyptic epic, the poem was published in three separate installments between 1976 and 1980, and in its entirety in 1982.

With his partner David Jackson, Merrill spent more than 20 years taking down supernatural communications during séances using a ouija board. Already established in the 1970s among the finest poets of his generation, Merrill made a surprising detour when he began incorporating occult messages into his work. In 1976, Merrill published his first ouija board narrative cycle, with a poem for each of the letters A through Z, calling it The Book of Ephraim. (The Book of Ephraim appeared as part of the collection titled Divine Comedies (1976), which was awarded the Pulitzer Prize in 1977. Divine Comedies also included the widely acclaimed shorter poem "Lost in Translation".)

In 1976 Merrill believed he had exhausted the inspiration provided by the ouija board. The supernatural spirits thought otherwise, commanding Merrill to write and publish Mirabell: Books of Number in 1978 and Scripts for the Pageant in 1980. The complete three-volume work, with a brief additional coda, first appeared as The Changing Light at Sandover in 1982.

In live readings, Merrill was able to impersonate the voices of poet W.H. Auden and his friend Maya Deren, as well as otherworldly spirit voices including Ephraim and Mirabell.

Writer Alison Lurie, a longtime friend of Merrill and Jackson, described the creative genesis of the poem in her memoir Familiar Spirits (2001).