East to the Grotto on the River Gave

There is a time portal north of Santiago, Spain, guarded by a young angel. Sometimes she opens this time portal and wanders through the rolling hills of Galicia and down into the city of Santiago de Compostela. In the 10th century, Spain is pushing the Moors back to Africa or killing them in their beds. One Moor escapes death by falling through the open time portal. In the 19th century, an Irish nun accidentally falls through the same time portal after walking the pilgrim's road to the city of Santiago. In the 27th century, Tucson, Arizona, is burning up. A lone environmental scientist remains to shut down all cooling generators and then leave the city to the sun's destructive heat. He too finds his way to the portal and plunges through to save his life. In the 18th century, a handsome sociopath charms the young angel into letting him use the time portal to escape criminal detection. In 21st century Puerto Rico, an old retired cop agrees to walk the Camino de Santiago with his granddaughter. In the same century, a child from Minnesota, traumatized by the death of her younger sister, agrees to walk the Camino as therapy for the tragedy in her life. The disorder of time brings them all together to expose a murderer, to rescue a kidnapped child, and to save the earth from a planet-destroying bomb.