When the dean of a swanky prep school is murdered, Shaw and Riley must dig into the toxic system of pressure on the students to succeed. Brady's son asks for a favor.
Matt gets jealous when Sean and Raj (recurring guest star Adhir Kalyan - "Aliens in America") starts to develop a father/son relationship. Christian and Liz try making things work.
When two Watchers end up dead by Kalas' hand, Joe realizes that Kalas is looking for Methos, the mythical "oldest Immortal."
As the fourth season begins, Lili Marquette (Lisa Howard) gives birth to a child that may be the last hope for survival of the Jaridians.
Anne responds to the call for help after an explosion devastates a subway station, but when another explosion rocks the station, Anne is trapped.