So I finally got the chance to watch the latest episode, and while I can't in all honesty say I loved it (I felt that the main mission-of-the-week felt a little too familiar and found it far too easy to figure out how it tied in to the Big Bad Season Arc), it was largely redeemed by the final act, in particular the incredible editing of a particular scene which really brought the viewer right into the action and confusion of the climax.
The above sentence is deliberately long in an attempt to illustrate what I mean... it's like it didn't pause for.. visual punctutation, so to speak. While Spooks has always had it's fair share of tense and suspenseful moments, it doesn't often feel this frenetic. I was literally on the egde of my seat. Brilliant.
As for that Big Bad Season Arc, we now know pretty much what The Evil Plan is, and OMG?!WTF?! we only have one episode left for Harry and the team to stop them!!!
The preview for the season finale? EPIC.
PS I want a Very Special Episode where Lucas North and Jack Bauer team up.