Zhishaa is the last Reiosian, and one of the main characters of the Black Nova universe. During a mission to use time travel to study a potential astronomical event that could threaten the future of her planet, her time machine malfunctioned and sent her exponentially farther than she intended to go. Trying to survive in what may be the last remaining inhabited star system in the cosmos, she hopes to enlist the help of the different sapient species on each of the surrounding planets in order to return home, only to be wrapped up in the problems of interplanetary politics and a potential war — particularly since some in power have realized she may possibly be able to give them exactly the technological edge they need to start a long-planned invasion of the other planets.