Every time the lights go out, someone dies...The TARDIS lands at an academy for top athletes, all hoping to be chosen for the forthcoming Globe Games. But is one of them driven enough to resort to murder? The Doctor discovers that the students have been hushing up unexplained deaths. Teaming up with a young swimmer called Emma, the Doctor begins to investigate - but he doesn't expect to find a squad of Sontarans invading the academy!