Ruthless Heir by Amy McKinley

A Mafia crown to claim …

The crown had always been Luc Savino’s. He just didn’t know it until a Chicago Mafia boss persuades him to board a jet and assume his destiny. But he won’t go without Summer—a one-night stand, his new, secretive executive assistant and probable spy for the former CEO of his latest hostile takeover.
She can only run so far before they find her…
After a mob boss viciously attacks Summer Johansson in her apartment, she flees the state to hide. But when she learns of her best friend’s murder and finds herself in the arms of a handsome stranger, her troubles escalate as she’s dragged into the heart of the very world she’s running from.
Secrets have the power to destroy, but hers will bring them closer…
Summer isn’t telling him everything, but Luc finds her impossible to resist. As their trust in one another grows, Summer’s enemies close in. Despite all the lies between them, it’s the truth that could tear them apart.