Unique among mission churches of the northern borderlands of colonial Mexico for its ornate architecture and rich iconography, San Xavier del Bac south of Tucson is a pilgrimage destination for countless devotees and tourists. Passing through the fa ade entry to stand in the nave, one is dazzled by the transept and sanctuary altarpieces of sculpture niches and baroque pilasters, as well as the expanse of the frescoed ceiling. This book...