A sinister 15th century black slate castle in north-central Portugal, overpopulated with insidious, all-knowing crows, is the setting for a mysterious inscription on a leper priest's gravestone. It reads: Fr. Joaquim, SJ, 32312 This dismal, dark edifice formerly served as a leprosarium for afflicted monks, now long dead, who pursued the practice of mining local ores during the WWII period. A Texas geologist and a French Jesuit priest are drawn into these ancient, crumbling ruins and unexpectedly encounter a mysterious, elderly black Mozambican priest on a mission of his own. The combined efforts of this unlikely triad decode the cryptic message from the grave and the trio is compelled to investigate an ancient Roman mine beyond the black castle walls. When the geologist descends into the hellish, forbidding depths of a near-vertical mine shaft, he makes a shocking discovery that cries out for justice.