Oliver suspects that Diggle's former mentor in Afghanistan is responsible for a spate of armoured truck robberies.
Clark and Lois investigate the apparent murder of Chloe but Lois's father, General Sam Lane, attempts to intervene. They suspect that he knows more about the case than he will admit, and discover he had recent contact with Lex.
During the renovation of an old house, Shannon makes a shocking discovery which leads her on an investigation that changes everything.
The agents may have uncovered the Cigarette-Smoking Man's true identity.
After she finds a human skull in the basement of her current project, Shannon sets out to discover who is behind the mysterious death by piecing together clues left behind in the victim's hidden diary.