After Safety Inspector Butch Hicks falls to his death off an offshore oil rig, Chief Vick enlists Shawn and Gus' help with the case. As she takes them out to the crime scene on the police boat, she tells them they received an anonymous tip that something highly unsafe was happening on the rig and the caller was risking his life to warn them. When Shawn and Gus ask why she didn't enlist help from her detectives or the Coast Guard, she tells them they are working more in an unofficial capacity. Just then, they are pulled over by the Coast Guard, whose commander, Barbara Dunbar, questions Vick's authority over the Hicks case. As they are arguing over jurisdictional lines, Shawn realizes they are sisters.