A former prison warden enlists the help of Walter to find a bullet that could prove the innocence of a death row inmate just days before his execution. Meanwhile, FBI psychologist - and Jeffersonian team member - Dr. Lance Sweets evaluates Walter's competency to consult on federal cases. In the process, Sweets begins to understand Walter's intangible gift and motivation to find the unfindable. Also, Willa attends a beach party and gets herself into trouble.