PERI: Wow. This is incredible.

ERIMEM: What are they all?

DOCTOR: Tardises. Or should that be Tardisi? Tardi? I'm never sure.

ERIMEM: But there are hundreds of them. What are they doing here?

DOCTOR: The relationship between Time Lord and Tardis is intricately woven. Once cannot exist without the other for long. When a Time Lord dies, their Tardis dies with them.

PERI: Then this is like an elephant's graveyard, only for Tardis-seseses.

PERI: Either the well was very deep or she fell very slowly.

ERIMEM: Why?

PERI: Why what?

ERIMEM: Why did Alice follow the White Rabbit with the strange obsession about time down the hole in the first place? It seems a rash and foolhardy action for so young a child. She ought to have had better sense.

PERI: Hmm. I feel a bit like Alice myself some days.

ERIMEM: And for that matter, what was a rabbit doing with a pocket watch?

PERI: It doesn't matter. Before you start to analyse the text, you have to be able to read it.

DOCTOR: Ah. It's rather as I feared. We're in the Axis.

PERI: The Axis?

DOCTOR: Yes. It's, er, a complex. Look, are you sure you want to hear this? We'll be on our way before...

PERI: Doctor!

DOCTOR: Right, well, er, imagine the spokes of a bicycle wheel. Each spoke is a damaged or truncated reality, a sort of dead-end in Time. They're formed by changes in established history, some big, some relatively small, which cause the flow of subsequent events to spiral out of control. Often catastrophically.