Key To Survival — Piers Anthony

Key to Survival is the fifth and concluding quarter-million word sexy ChroMagic fantasy novel. It features King Havoc, Queen Gale, and their four Glamor children as they tackle the invasion of the machines. The machines have destroyed one third of the galaxy and are working on the rest. They have overwhelming power and ruthless competence. But one thing makes them pause: they want to recruit Havoc's daughter Voila to their cause, as she is the strongest of all glamors with a talent they need. If she joins them, they will spare the rest of the human culture--and destroy the rest of the galaxy much faster. This is an offer Voila has to think about: whether to betray all the other living cultures, to save her own.