The Yellowstone Volcano was an extinction event. The Monitors wanted to be here to see it and to see how humans coped with such a catastrophe. Within three years, Ann Jacob went from a 62-year-old married retired teacher to a vampire's true love in the prime of her life, but with the wisdom of her age. Marco Antonio, the 700-year-old Monitor who lived off human blood so that he could store more neuronal tissue in his body cavity, convinces Ann that he can be monogamous when he changes one gene. He is not prepared for the emotional intensity he will experience as a result, and he must learn to deal with jealousy and rage. The Monitor's outpost at the Mariana Trench has been buried in a mudslide, and he must contend with that while dealing with the non-ethical practices of some of the other Monitors who will cut corners to find a cure for Marie's Disease, which is affecting the lungs of all the vertebrates on the planet. Ann is very aware of her position as primary interplanetary liaison, and tries hard to help the Monitors blend into human society and to provide emotional support for Marco Antonio, the most brilliant bio engineer on at least two planets. He must switch from one body to another through a transmission vial because humans cannot survive at such deep ocean depths and Monitors are afraid that their true octopus-like shapes would frighten people. One of the other Monitors who has used human vivisection in his lab and has been banished for it steals his transfer-vial and throws it over the cliff into the deepest part of the trench, making it impossible for Marco Antonio to return to Ann. He must leave much of the knowledge stored in his huge brain at the bottom of the sea, making his emotional control even more tenuous. Dealing with jealousy, possessiveness and rage in a man whose brain is powerful enough to kill with a thought is a challenge that Ann must accept if she wants the relationship to last. Every vertebrate on the planet is dependent on Marco Antonio being able to find a cure for Marie's Disease before there are mass extinctions, so the consequences for failure are too great to consider. Marco Antonio is too big to fail, and Ann realizes it. She must help him cope or leave him.