The Dauntless - Spy Girl, #5

Can one girl save the world? Huntley Von Allister's cover is firmly in place. She's brilliantly completed her first four missions. But she is done. Done working for Black X. Done trying to untangle the mystery of what got her mother killed. And very, very done with love. She's given herself a simple mission-to recover the precious memories of her final days with her mother by visiting the places in the photos left behind.
Well, that, and to discover who owns the emerald rings, like the one she found on Dupree. And completely destroy their secret society.