S4E12 : A Very Juliet Episode

In 2003, Juliet made a pact with her boyfriend Scott Seaver to meet up in seven years. After he fails to show up, Shawn finds him, and by extension endangers his life since he was a key witness against mobster JT Waring, who was convicted for the murder of a US Marshall. When Waring denies killing the Marshall, Shawn must prove him right in order to protect Scott.