So just finished catching up from Season 1 to the latest Season 4 episode - I fully enjoyed season 1 & 2, I liked most of Season 3 until the "silly" last episode as, with nearly 20 people dead and it being on the news, it'd be impossible to cover-up that level of death. Season 4 is off to a slow start which I'm fine with, although I don't like the new head Dog or First Desk as neither seem competent enough to actually be in their roles, or the two new faces amongst the slow horses who've had almost no time to do anything other than a single line about their history so far, but hopefully that'll change.