Apart from the company of her flying pet ferret Fernando and her auntie Carla, 13-year-old Nessa Santiago is alone. Her mother died in a circus accident in Spain and she never knew her father. But then the day finally comes for Nessa to meet him and everything goes wrong. Her auntie unexpectedly leaves their home of Wye River in a helicopter. A menacing Cryptid Hunter, who captures unusual creatures like Fernando, shows up instead. So in order to keep Fernando safe, Nessa must run.
With help from Kep, a boy from her school, Nessa embarks on a wild journey to her father’s home and then the Hawkesbury River. They are pursued by the anti-cryptid organisation HARNESS and a mysterious giant bird in the sky. Along the way, Nessa, Fernando and Kep meet weird and wonderful creatures, but with each new encounter, more questions arise. What are the visions Nessa gets every time she closes her eyes? And what are they trying to tell her about her parents?