It was an innocent enough advertisement but curious.
"WANTED, by Retired Clergyman, Secretarial Assistant with courage and imagination. Tenor voice and some knowledge of Hebrew essential; single; unworldly. Apply Philip Skale . . . '

Robert Spinrobin applied. Later, struggling to keep pace with his new employer as they strode across the steep valleys around Skale's isolated house, he was swept up in the sheer enthusiasm and urgency of the man. But a thin trickle of fear warned him that he was embarking on the greatest adventure of his life.

Was it possible that Philip Skale had discovered some hidden power of sound which held the entire universe in its pulses? Could it be that the uttering of a word, a name, the Name above all names, might suddenly unlock the secrets of life and death?

No single voice was capable of it. Four voices were needed a human chord in perfect harmony. So Philip Skale had gathered the four of them together into his household Mrs. Mawle, the alto; Skale's niece Miriam, the soprano; Spinrobin; and Skale himself, whose rich bass would complete the chord.

But suppose it didn't. Suppose, when the great hour came, something went wrong, and what was summoned was not God but the Devil, not a new creation but the destruction of all created things.

Spinrobin, on the verge of finding unhoped-for happiness, seemed alone in realising the possibility of awesome danger.