[Siren Classic ManLove: Erotic Alternative Paranormal Romance, M/M, shape-shifters, vampires, HEA] After hundreds of years on Earth as the right-hand of a powerful regime, Kellan has more regrets than he can count. He has never hesitated to put the needs of his Coven first, but a dangerous mission sends him on a collision course with the one man who can make him rethink his priorities. Panther shifter Mason has lived with an all-consuming guilt for far too long, and he jumps at the opportunity to make things right without understanding the danger he faces. Opposite in every way, these two men have to work together to protect information that could save or destroy lives. Doing their duty may mean confronting their differences, flaws, and more importantly, their need for each other. Will they fight their fate and turn from each other, or will they acknowledge what a perfect pair they make?