Revenge can be sweet, and so are Joanna Coffee's ristrettos. When her ex, Detective Quentin Perry, approaches Jo with a case that seems to be rooted in revenge, Jo has to agree. The victim, a nighttime security guard, was stabbed to death in a way that says this is personal. With no witnesses and no murder weapon, Jo doesn't have much to go on. And several people had motive to want Simon Porter dead. Someone is...