The Jaz Parks series is an urban fantasy collection of spy-fi novels by American author Jennifer Rardin.

The series is set in a contemporary world in which mythological beings such as vampires and several less famous creatures are real, and follows the efforts of the Central Intelligence Agency to combat paranormal threats to national security.

The focus of the tale is CIA operative Jasmine "Jaz" Parks, who is regularly partnered with her boss, the enigmatic vampire Vayl.

[1] The series' wise-cracking protagonist, Jasmine Elaine Parks is a CIA assassin who is regularly assigned to paranormal cases.

In addition, she is a noted sharpshooter and possesses an ability to detect the presences of vampires, while also being highly resistant to several of their powers.

A vampire who was born in Romania in 1744, Vayl is now a CIA official who regularly serves as Jaz's field partner and direct superior.

He is a generally guarded, enigmatic figure who harbors trauma relating to the past and his children, whose deaths he unwittingly caused.

His eyes change color depending on his emotions, e.g. emerald green for desire, black for extreme anger (but only Jaz is able to tell).

[8] Publishers Weekly called Once Bitten, Twice Shy an "entertaining but derivative debut," going on to say that "Jaz's jittery narration amuses, but the fang-filled plot, replete with action licks and paranormal theatrics, will have trouble standing out in this overcrowded field.