Chief (Kings of Guardian #7)

Cloaked in the identity of David Xavier, a billionaire player in multiple world theaters, Mike White Horse worked to enter the Russian Mafia’s lair, by stalking a shadowy creature named "The Concierge." The Russian woman brokered young innocents into slavery, and Mike meant to destroy her and the organization she worked for. He should have despised her for the atrocious crimes she facilitated, but too often love and hate are the flip sides of the same coin, and what Mike felt for Taty was not hate. It didn't matter. He'd destroy the Bravata and all its associates--even if it meant part of his soul sat in prison for the rest of her life.

Driven by heartbreak, Tatyana Petrov joined the elite British M16 unit, and for eight years, wormed her way into the trust of the Bravata as she strove to identify the human filth selling those innocents to billionaires like David Xavier. She'd found it easy to loathe the wealthy men who bought her "toys"--until David. For reasons that she wouldn't acknowledge, she wanted to protect this one man from the retribution rapidly approaching.

Neither knew the other's true mission but even as mortal adversaries, they'd each given the other a part of their soul, and now only devastation and sorrow waited.
Rated '4/5 - Explicit open door' for steam/spice/heat level.