The Doctor and Donna arrive in ancient Pompeii a day before Vesuvius blows.  They discover that they must leave soon yet Donna wants to try to save everyone.  The Doctor tries to tell her that they cannot change Time that way.  They then find out that there are seers in town that know all about who they are and where and when they come from.  With Doom approaching, can the Doctor and Donna work out their differences and escape before being burned alive?