Mason Navarro fled his brother's clan years ago and made a name for himself as a premier fighter in an underground fight club. Dr. Shane Lawson is a world-renowned scientist specializing in vampires and various matters relating to blood. When Bryn Navarro comes seeking help, neither man can refuse him. The clan is readying for all-out war with a demonic force hellbent on wiping them out. It's going to take Mason's training and Shane's knowledge to keep them all from succumbing to the dangers of demonic blood. But demons don't play fair, and Mason Navarro is forced to make a decision: stay hidden in the closet, or save the man he loves more than life itself.