Sara, a sophisticated sculptress, and the languorous Samuel, whose wealth and lifestyle have driven him to a state of perpetual ennui, are caught off-guard by their young relative's report of an ecstatic, mystical vision.

His pronouncement is the cause of much discussion and consternation among the adults present: Julie McMoon, a neighbour of the Dunns who is grieving the recent suicide of her husband, and whose children are attending the summer school; the cynical pianist, Richard Lundrigan, who will spend much of the novel attempting to convince Cowley that his vision was a fantasy; and Thomas Lavender, a highly enthusiastic, if not slightly crazed, minister, who has joined the vacation in his capacity as Cowley's spiritual director, and is convinced of the veracity of his protégé's mystical experience.

Also party to Cowley's mysterious claims are his students, Ellie Sonntag, Daisy and Timmy McMoon, George Bundle, Fendall Dunn, Rufus Este, and Harry Fogg.

The vision, however, is revealed to be the children, who, on overhearing that the adults intend to seek the miraculous, have decided to play a trick on them, enlisting the help of Sara's model, Mollie Purdue, and dressing themselves in white sheets.

At the close of the novel the ageing minister's desire to partake of that innocence manifests itself in ways both strange and tragic, first in his performance of a bizarre marriage ceremony, wedding the children to one another, and then in his fatal fall from their tree house.

Following its publication, the novel drew the following comment from Caspar Weinberger (later, in an article written for the San Francisco Chronicle: ‘It is not too much to say that among America’s current novelists his abilities are the most obvious and his ultimate place is with the best we have produced’.