Concluding volume of The Quintara Marathon trilogy (The Demons at Rainbow Bridge, The Run to Chaos Keep), this one galloping all over the alternate dimensions and told in three modes of internalized or telepathic nonverbal communication. Book One found the awakening from suspended animation of some nasty, taloned, horned demons who were affecting Earth culture as well as every society in the three galactic empires: The Exchange, the Mycohl, and the Mizlaplan. In Book Two, a scientific team sent by the Exchange was slaughtered by the demons, and small rescue teams from each empire pursued the monsters through an interdimensional gate. Here, the three empire teams forge into one team of five Terrans that has chased the demons of ultimate evil to a city of the damned on a desolate planet ruled by The Other, the master of the Quintara, an unseeable, mind-blocking creature ``at the heart of this horror.'' Even the demon princes are as dust specks compared to The Other. Will The Other--Baal--turn the present and future populations of the three empires into 90 trillion Fausts? Only the martyrdom of small, sandy-haired Irishman Jimmy McCray, who plunges a crucifix into the Evil One's chest, can save the nondemonic beings in all dimensions as we will know them--tomorrow? Superpulp.