Stella and Aiden investigate when the body of a teenage girl is retrieved from the harbor. They soon realize that she was a middle-class girl attending a fancy school who was trying to make it seem like her family had more money than they did. Mac and Danny investigate when a body is found in a construction tunnel for a new part of the city's water supply. However, they end up running into difficulty when the Sandhogs, a union for the tunnel's diggers, blocks many of their attempts to get information about the victim.