Letty Valdez is a Chicana-Native American (Tohono O'odham) private investigator and Iraq War veteran in Tucson, Arizona. Letty is hired by her friend librarian Seri Durand to investigate a murder in Seri's library. Seri's work colleague had encountered an intruder in the library and was stabbed to death as a result. Seri hires Letty to find the killer. They both suspect the murderer was searching for a specific item because library materials had been disturbed. Almost immediately Letty becomes a target. She has to deal with a mugging, a home invasion and a shootout on the Tohono O'odham Reservation in her attempts to find the criminal who is targeting her. She struggles as well with PTSD nightmares from her experiences in Iraq. Then Letty finds a clue to the murder mystery in a memoir donated to the library. Significant passages of the memoir were written by a Tucsonan named Pete Arianos. Pete, who was a boy in Tucson in the late 1890s, was the son and step-son of an Italian and a Chinese immigrant. The Chinese man, Xia Yù Long, was an anti-Q'ing Dynasty revolutionary who fled Hong Kong in 1895 to find a new life and a new love in America. In Tucson he comes to be known as known as Drago Shaw. Letty is helped by her friends and family and a new canine addition to the family, Teddy the Black Lab sniffer dog. Like all Letty Valdez Mysteries, there's excitement, intrigue and a touch of romance in Dragon's Revenge.