More from the Press Screening

Den of Geek's report is generally spoiler-free but they do say that if you want to watch the episode cold, look away now... Here is a snip:

The bringing back of The Master, and the episode gets down to business very quickly, isn’t quite so impressively done, although it's done quite swiftly. It’s also utterly fair to say that he’s even more insane than he was in The Last Of The Time Lords. This is not a quiet and reserved Master at all, and we suspect he'll remain as divisive as the last time we saw him. We've always liked The Master a lot though, so were pleased to see him, and he does get some quite scary moments. He comes across as frenetic, random, hungry and very, very dangerous.

Total SciFi Online also have a report, which is more spoiler-y than the above! As ever, if you want to know nothing, then don't read :)

Along with Cribbins, Simm is the driving force of this episode, utterly different from his Harold Saxon persona from two years back, yet totally the same character in his wild-eyed, evil genius. Several Master moments in the episode are genuinely scary, and yet wonderfully funny at the same time. It’s a perfect combination for a man who reviles yet revels in his own lunacy, and makes for unforgettable telly. The fact that the Master seems to have no distinct plan until late in the episode makes it all the more breathtaking when it finally kicks in – and reminds us how terrifying a Time Lord can be, if you don’t have him on your side.

Annnnd we have some videos too!

(And a better quality version of the video I posted the other day...)