The Keeper of Flames. Jayne Thorne, CIA Librarian, #3

A lost fire goddess. An arrogant new ally. And a secret magical society on the brink of extinction. All Jayne Thorne wants to do is work with her sister to track down their missing father. But instead, she is tasked with another assignment from the CIA: go to Rome and acquire a necromantic grimoire linked to a lost fire goddess. As Jayne struggles to work with her new partner, a smug and infuriating magician who knows exactly how to push her buttons, she realizes this mission may reveal clues to her father's whereabouts.
To make matters worse, the deadly terror organizations have caught wind of this powerful grimoire, and their dark magic has created all manner of terrifying new obstacles for Jayne to overcome. The closer Jayne gets to finding her father, the more she uncovers about the secret society he was part of. When she realizes their enemies are closing in on these hunted magicians-and targeting her sister, too-she must expand her magical abilities, trust in her partner, and risk her life for the truth...
or else the power of the fire goddess could wind up in the wrong hands.