The Observation - Brotherly Bond, #3

FBI agent Thomas Mason is on the hunt for his wife's killer, even though he's been ordered to leave the case alone. Teaming up with his old special forces squad mate, Jude Scott, seems like a good idea until Agent Mason discovers Jude is working for one of the prime suspects. Mason wants answers or he'll end their friendship with a bullet. Jude is conducting an investigation of his own. Someone is targeting people who take the wonder drug, Clarity, made by the enigmatic pharmaceutical company Jude works for.
He's blindsided when the killer strikes close to home, putting the woman he loves in the crossfire.