Into the Fire by Michelle St. James

All’s fair in love and war — and sometimes it’s hard to tell the difference. Damian Cavallo would do anything to get Aria back — even join the Syndicate. Fresh on the heels of Aria’s rescue in Greece, he joins up with the other Syndicate leaders to take down Primo Fiore and his dangerous first-in-command, Malcolm Gatti, but Primo and Malcolm have aligned themselves with a new enemy: Stefano Anastos, notorious head of the Greek mob. And taking down both armies won’t be easy.

Aria is still recovering from her kidnapping when she gets a call from the one person she has no choice but to love — her brother, Primo. Determined to help him in spite of everything, Aria sets in motion a series of events that may prove deadly for more than just her and Damian. Then the violent turf war returns to New York City and Aria is forced to make an impossible choice — save the man she loves, save her brother, or sacrifice herself.