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.
Still feeling responsible for Don's near-fatal stabbing, Charlie puts his focus into tracking down an unnoticed serial killer, with the agents revisiting math theories from when Charlie first started working with the team to help solve the case.
S5E521 41 min
