S1, E9: The NATS attend a class with guest speaker Dr. Susan Langdon, played by Anne Heche. Dr. Langdon is a former agent and profiler who tasks the trainees with looking at serial killer cases to find the one victim that doesn't fit the case, but when Simon becomes too good at finding things that don't belong, it's his life that becomes endangered. In the future, Alex is interrogated by a highly sophisticated FBI team while Ryan's life hangs in the balance.