SPOILER ALERT
Episode four of the new series of Doctor Who - The Power of Three - was aired last night. The episode started off slowly at first - but then suddenly burst into life.
The episode saw Earth suddenly invaded by millions of mysterious little black cubes. These plain black cubes, about the size of Rubik's cubes, appeared to have no purpose. They fell all over the planet. People gathered them up and took them into their homes and offices, using them as paperweights or for what ever other purpose they could find.
Months went by with nothing happening.
Then, one day, the cubes started springing to live, and the number 7 appeared on them. Then 6. Then 5. And so on. The cubes appeared to be counting down to something.
But counting down to what?
This series also featured a cameo by Professor Brian Cox.
Here's more....
Doctor Who prepared to say goodbye to Amy and Rory in The Power Of Three
TV review: Doctor Who will bid farewell to Amy and Rory Pond next week and although their penultimate episode The Power Of Three initially seemed tame, it soon ramped up the drama.
22nd September 2012
The Power of Three, aired last night on BBC1, sees Earth invaded by millions of mysterious little black cubes
The Power Of Three served two purposes. The first was, as usual, to tell a pacey, compelling story - this week, one that involved the sudden global appearance of millions of small black cubes, which provided the traditional solve-the-mystery-then-solve-the-problem plot for Doctor Who.
The second, perhaps more important purpose for Doctor Who fans, was to pave the way for Karen Gillan and Arthur Darvill's exit in next week's episode.
This began almost as soon as the episode did, with Amy and Rory discussing whether or not they wanted to stay with the Doctor.
'What do we do?'
'Choose?' replied Rory.
It seemed initially as though The Power Of Three was going to be a very casual pre-departure episode. After all the build-up to their exit, there seemed to be a lot of sitting around on sofas and pondering whether they should remain as the companions of the time-traveller or stick to their day jobs.
The Doctor, surprised that the pair had careers at all, was met with the question, 'What do you think we do when we're not with you?'
A very good question. And we all got the answer, more or less, when a glimpse into the mundanity of the Ponds's lives was offered.
As 'Team Cube' tried to uncover the truth about the mystery objects, Amy, Rory and the Timelord himself spent an inordinate amount of time in the Ponds' living room, even going so far as to pass the time by carrying out some household chores.
The Ponds seemed to have realised that what the Doctor does 'isn't all there is'. It was a bit of a big, already-obvious, realisation to come to all of a sudden, but the end result will still be a moving one: The Ponds will depart.
As usual, there was still plenty of humour along the way in tonight's episode too, with everything from Twitter to Alan Sugar coming under fire. And as for initial concerns about it being a low-octane episode, well, those cubes turned out to provide plenty of drama after all...
Professor Brian Cox appeared on TV as himself trying to explain what the mysterious cubes are in the latest episode of Doctor Who
Read more:
Doctor Who, The Power Of Three, series 7, episode 4: TV review | Metro.co.uk
The episode - The Angels Take Manhattan - sees the departure of Rory and Amy. It will be only the second episode ever to be filmed in the United States.
The Doctor gets a new sidekick in this year's Christmas special.