Williams gives a contemporary setting to the traditional story of the Search for the Holy Grail. Examining the distinction between magic and religion, War in Heaven is an eerily disturbing book, one that graphically portrays a metaphysical journey filled with marvels and black magic, God and the Devil.

"The telephone was ringing wildly," begins War in Heaven, "but without result, since there was no-one in the room but the corpse." From this abrupt - and darkly humorous - start, Williams takes us on a 20th-century version of the Grail quest, with an Archdeacon, a Duke, and an editor playing the old Arthurian roles. Throughout, Williams reminds us that these legends were above all about divine, not just human, romance.