FBI-agent Don Eppes (Rob Morrow) har et hemmelig våpen i sin yngre bror, Charlie (David Krumholtz), et mattegeni som bruker ligninger til å løse forbrytelser.
Agent Colby Granger lands in prison after the discovery that he was a mole within the FBI, but he escapes, and it's up to Don and his team to track him down and uncover the truth on the fourth season premiere.
S4E401 41 min
