Casting spoiler for finale

[Dr. Horrible]

^The point, surely, is that the first Doctor knew the Master when they were children.

 

[Da'an]

I don't get the comment about different numbered doctors having or haven't met the Master. It's the same character. If the Doctor has met the Master, then the Doctor has met the Master, regardless of which regeneration he was on at the time.

 

[intrinsical]

I don't know about anyone else, but when I heard "He will knock four times" I immediately thought of the Master. Has everybody forgotten "The Sound of Drums", the Archangel Network's broadcast of four beeps, The Master's drum tempo of four beats?

 

[Gepard]

And anyone who might recall the sound of drums when the woman at the end of PotD said HE will knock four times...

I have to agree that is hardly conformation.

Well, my roommate figured it out right away from that line. (We were talking about the episode after it was over, and he reached over to a wall and started doing the ratta-tat-tat thing from "The Sound of Drums." )