The Fires of Pompeii (S04E02)

In the episode "The Fires of Pompeii," the Doctor brings Donna to Pompeii on the fateful day when Mt. Vesuvius is set to erupt. Confronted with a significant ethical challenge, he must decide whether to intervene and alert the townspeople about the looming catastrophe or allow history to unfold as it was meant to. As they navigate this emotional journey, the Doctor grapples with the consequences of altering the past while Donna seeks to understand the weight of their choices.