A so-so episode, I thought not disappointingly dreadful but for me it didn't reach the heights of the past few installments. Hopefully things will pick up in next week's finale.
A few thoughts, masked by a cunningly constructed perception filter... 😎
A bit of idle speculation to start off with... I'm guessing that the Toclofane are the Time Lord children who were sent mad by the vortex. It wouldn't surprise me given some of the nastier and darker aspects of Time Lord society that they'd quietly try to dispose of these 'failures', unable to brig themselves to kill them so instead imprisoning their crazy little minds in the void or an alternative dimension or something. I think the Master referred to them as 'kids' at one point, and they did seem to have a childlike way of talking. Mind, it doesn't explain why the orbs are fitted with blades and lasers...
That would also set us up for the Doctor to have to face an emotional dilemma save the Earth but destroy the last remnants of the Time Lords. RTD laps that sort emotional cliffhanger right up. 😉
I did like the little conversation between the Doctor, Martha and Jack about the Doctor and Master's past *I suppose that puts to bed the "Doctor and master are brothers" debate that's been going on for 30-odd years, unless of course the Doc was fibbing. 😛
And the poor Tardis the old girl didn't look well at all. It was quite poignant too, hearing the cloister bell ringing away... like the Tardis had spent the last 18 months calling out for help but no one came. It doesn't look like the sort of thing that can be easily rectified and the 'next time' trailer shows a large explosion in the console room does this mean that we could see the Doctor Earthbound for a spell while he fixes his machine, a lá Pertwee?
<subconsciously taps MacBook's palm rest rhythmically>