In his excellent A Thief in the Night (1989), Cornwell looked into rumors that Pope John Paul I had been murdered. Here, the former seminarian conducts a yet more subtle and meaningful investigation--of the ``incidence and significance...of paranormal religious phenomena'': flying monks, weeping statues, divine apparitions, and the like. A professed agnostic, Cornwell a few years ago found his nonbelief undermined when he experienced a prophetic ``religious dream.'' His curiosity aroused, he set off on a worldwide hunt for earthly signs of a divine hand, beginning with a visit to the Yugoslavian town of Medjugorje, where, for years, three children have allegedly been conversing daily with the Virgin Mary. Although repulsed by the commercialization of the phenomenon--with souvenir- vendors and millions of tourists creating a ``spiritual Disneyland''--Cornwell found the sight of the children ``speaking silently'' to the invisible Virgin ``truly astonishing,'' with one girl's eyes seeming ``to shine with an unearthly light.'' But what to make of this? And of his subsequent experiences, including witnessing the stigmata of a Montreal recluse, the liquefaction of the dried blood of St Januarius in Naples, and the devotion inspired by the alleged miracles of Padre Pio (healing, stigmata, bilocation)--and, on the dark side, the terror of a man supposedly possessed by evil incarnate? As a journalist, Cornwell's trained skepticism compels him to dig out mundane, generally psychological, explanations for nearly all; and yet he finds himself profoundly moved by the ``symbolic'' power of these ``miracles,'' declaring- -especially after soul-stirring meetings with Briege McKenna, a nun with an apparent gift of healing--that the importance of ``prodigies'' lies not in whether they offer ``supernatural `evidence,' '' but how potent they are as living ``symbols'' of the ``religious imagination.'' An affecting personal spiritual memoir as well as a tantalizing tour through the miraculous, which reveals its mystery- -if not its secret--under Cornwell's fresh and compassionate gaze.