A text message from an unexpected source has both the Ravens and Byrd on edge. Neckbone pays an unannounced visit to the Ravens at their off-duty hangout, asking pointed questions and leaning on the cops to find the source of WMD, a powerful new synthetic drug that's cutting into his business. Lourdes makes a discovery that Ramos is hard-pressed to explain. Lourdes' father, Colombian cartel lawyer Victor Morales challenges Ramos about his ability to ensure the safety of his wife and their young daughter Veronica. Meanwhile, the lines between friends and enemies begin to blur for Byrd. Beach's clandestine romance with Vipers gang member Sam Foster complicates the Ravens' lives in unexpected ways.