The Chicago murder rate is on the rise, and amidst the insanity, Diane, Lucca, Maia, and the rest of the law firm find themselves under psychological assault when a client at another firm kills his lawyer for overcharging. Following a copycat murder, the firm begins to look at its own clients suspiciously. Meanwhile, Diane battles with a new partner at the firm, Maia becomes tougher after her parents' scandal puts her on trial, and Lucca is brought back into the orbit of Colin.