Twisted Loyalties. Kings of the Underworld, #4

Twisted Loyalties - A Dark Mafia Romance | Book Four of the Kings of the Underworld SeriesHe was supposed to use her. She was supposed to deceive him. Neither expected to fall. Leonid is a cold-blooded killer-ruthless, calculated, and loyal only to his inner circle. As the deadliest sniper in Russian mafia history and a powerful underboss in the U. S. branch of the Organization, he's earned his place through violence and fear.
But behind the ice in his eyes lies a secret he's willing to die for. Sierra has spent her life in hiding. Daughter of a brutal Mexican cartel boss, she's on a mission to find her missing sister and escape her father's legacy. When she's offered a job as a billionaire's personal assistant, she sees an opportunity to disappear in plain sight. But nothing is as it seems. She's not just an assistant.
He's not just a billionaire. And their dangerous attraction is more explosive than either of them can control. In a world where betrayal is currency and love is a weakness, Leonid and Sierra are forced to choose between loyalty to their blood. or surrendering to a love that could destroy them both.