The Doctor meets Caecilius
A few thoughts about this episode:
"You have something on your back". That was creepy.
The explanation of the stone monster's plan was a bit rushed and technobabbly and I still don't understand it.
I'm sorry, but not even the Doctor can outrun a pyroclastic surge.
Loved the pop culture reference jokes - the Mary Poppins "Positions!" and "She's...from Barcelona" had me LOL!
But best of all for me was Caecilius! He and his family (well, except Evelina who they made up) were all named after the characters in the Cambridge Latin Course, which was the textbook we used at school. It was all about the Caecilius family in Pompeii, and at the end of the book they all died in the eruption, except for Quintus and one of the slaves. As soon as the stall holder mentioned Caecilius I was "What?? The Caecilius?" A quick trip to the TWOP Doctor Who forum confirmed that it was indeed a deliberate reference. It made me all nostalgic and happy. :)
And if any of you ever have the opportunity to visit the real Pompeii, go. It is utterly fascinating, and I would love to go back there. The site is so huge it needs more than one visit for proper appreciation.