City of Death.

On an unrelated note, a dramatic DA-DA-DA-DUM, DA-DA-DA-DUM plays during the climax of The Deadly Assassin, which is creepy since it involves the Master opening the Eye of Harmony and reality going wacky.

And yes, that is also the climax of the Eighth Doctor's movie. Wonder where they got the idea.

Didn't Moffat say the crack idea came from his son's bedroom wall?

OHES NOES!

So the Crack got all the way back to those episodes. xD

And as for the Master Four Drum thing... =O

In my experience, one should never ignore coincidences. Unless you're busy, in which case you should always ignore them.

(LOL ELEVENTH DOCTOR QUOTE)