Conbryo
It didn't sound like tSoD to me. It sounded like a heartbeat...and I usually pick up that beat pretty quickly. It might have been tSoD, though. I just disagree. It's too soon after the Master's last appearance, they can't have the same bad guy appearing season after season. That's why I'm sick of the Daleks: they're overused. Way overused. Every single finale.
The Daleks weren't in the The Sound of Drums. They've been in every
season, but not every finale. And, really, the fact that they keep coming back is nothing new in the history of the show.
The beat I'm talking about kicks in at 26 minutes and 24 seconds into the episode; the beeping that precedes Harriet Jones' transmission over the SubWave network. It's definitely the same beat as the drumming. Further more, they used the same note as was used in track 21 of the season 3 soundtrack where they used that beat, at 24 seconds.
I'm not saying that the Master is coming back for the finale. In fact, at this point, it would be a little much to try and deal with. But do recall a couple things:
1. There was the lady picking up the Master's ring at the end of The Last of the Timelords. We still don't know what was up with that.
2. Harriet Jones mentioned that the SubWave network was created by the Mister Copper Foundation. What the heck is that!?!
3. The Archangel Network from The Sound of Drums was just as sophisticated. The Master has built something like this before.
So, all in all, while I doubt rather highly we're going to be seeing the Master this series (in fact, RTD has actually said we won't; he yanks our chains, but he has never all-out lied), the hints would seem to indicate that he's out there, in some form, still.
Berz.