The Doctor wanted to take Donna to Rome but soon they find out that they landed in Pompeii instead. On the next day, the volcano will erupt but the people in Pompeii don't know about it. Donna wants to save them but the Doctor tells her that Pompeii is a fixed point in time that can't be changed. When they want to leave, the Tardis is gone which leads them into the house of a Pompeiian family. There they find out, that many people in Pompeii are able to make predictions and that these are always true. The Doctor soon thinks that some kind of alien has to be the reason for that and that turns out to be the truth. Soon the Doctor is faced with a horrible decision between the destruction of Pompeii or the destruction of the world but he has Donna at his side who supports him. Is everybody in Pompeii doomed to die?
Somehow the episodes with Donna as a companion always have some funny moments in them. There is just this great chemistry between her and the Doctor especially when people think they are a couple. I think Donna would go everywhere with the Doctor but she is nobody who holds her tongue when she thinks the Doctor is wrong in his decisions. This also happens in this episode when she persuades him to save the family. The episode has an interesting story and I think it was a great idea that the Doctor was the one who decided that Pompeii had to fall. He didn't knew about it before but I guess even a Time Lord can't know everything. An interesting episode in a historical setting.