Books like Vigilant by James Alan Gardner

On Demoth, humans and the winged Ooloms lived in uneasy harmony until a horrific plague decimated millions of Ooloms while leaving humans intact. Faye Smallwood, a caretaker in her father's hospital, witnesses the devastation and later the accidental death of the scientist who found the cure that earned him acclaim. Seeking escape from her past, Faye joins the Vigil, a group of independent monitors tasked with exposing governmental corruption. Connected to the planet‑wide datasphere, she receives a cryptic vision of peace that turns into a deadly threat. As she becomes a target of assassins and uncovers a sinister plot to unleash a new, more lethal outbreak, she discovers that Demoth’s ancient ruins hide alien technology capable of immense power. Faye must navigate betrayals from within her ranks and collaborate with the enigmatic explorer Festina Ramos, whose vigilance for society’s marginalized may hold the key to saving both humans and Ooloms.

First publish date: 1999