Killers: (A Prosper Snow novel)

Murder makes monsters of people. Prosper Snow knows that better than most. Now he's back on the trail of another serial killer, only this time there's far more to the case than meets the eye. Thwarted at every turn, Prosper unwittingly uncovers a human experiment more monstrous than anything he could ever imagine. Now the only way to crack the case is to work from the inside and join a shadowy government agency that operates outside the law. Only he might be too late as the experiment has spiralled out of control.