You can find the official ebook and audiobook versions through major retailers and digital libraries:

Instead of completing his deadly assignment, Beast finds himself unable to kill her. Overcome by a sudden, protective greed and desire, he chooses to take her for himself instead.

The book is the first part of the Beast & Beauty Duet and features heavy "forced proximity" and "possessive hero" tropes. Where to Find the Book

During his mission, he encounters Aurora , the man’s innocent, black-haired daughter.

Beast is tasked by his "owner," Lex, to hunt down a man and destroy everything in his path.

BEAST (A Dark Mafia Romance) (Beast & Beauty): Wild, Clarissa