River is convinced that Stevie's investigation into the exploitation of undocumented migrants holds the key to her murder. Further questioning of someone close to the team reveals a system of immigration cases that could lead into some very unexpected places. When a common link to certain businesses is found, it all starts to fall into place for River, with unfortunate repercussions. As Stevie's loved ones reel from the truths unearthed, River holds the future in his hands. How will he keep his final promises to Stevie? How can he keep her secrets for her and do what is right? And, if he solves her murder, can he cope with losing her forever?