The central conceit of this elegant, accomplished contemporary ghost story is that fuentes--springs in which children have been ritually drowned--are portals of inexact time travel. A byproduct of the ritual, and of time-traveling, is that memory is cast off in the form of a crystal stone, which allows its holder to experience the cast-off memory, which ""might be transferred to living flesh."" Hale Appleton, leader of the Societas Fraternia, a spiritualist cult, creates one such crystal in 1884. The stone is then stolen, and pursued to the present day. Timelines and characters overlap here. Scenes from previous centuries take place on the periphery of the present story line, wherein Phil Ainsworth, an insular photographer who lives in Southern California, where Appleton made his sacrifice, gains custody of his niece. People from the past and present converge on Ainsworth in an attempt to get the crystal, or to block the portal--a well on his property--from being neutralized. Ambitious plotting and characterization augment Blaylock's (Winter Tide) lush language (ripples in a well ""cast a hundred shifting shadows... crisscrossing in geometric confusion""). This is one ghostly tale that stands on very solid ground. (Aug.) FYI: Blaylock has received two World Fantasy Awards, one for best short fiction (""Paper Dragons,"" 1986) and one for best short story (""Thirteen Phantasms,"" 1997).