A pretty solid start to perhaps the darkest and most depressing corner of Doctor Who.  Children of Earth is overall very good, a strong experience overall, and everything is nicely set up here.  Frobisher has a memorable introduction here thanks to Peter Capaldi.  It's neat seeing him hear in hindsight, knowing now that he would eventually become the Doctor.  Even at the time, having no idea myself who Capaldi was at the time, I really liked him and he stands out as a very significant and dark Doctor Who villain.  Frobisher isn't strictly evil, but he represents that particular brand of human evil laced in bureaucracy and the coldness of professionalism that plagues modern neo-liberal imperialist governments.  This is Torchwood as it always should have been.  Political, clever, and a thriller that keeps you right on the edge of your seat.  Sure, Children of Earth has an advantage over the first two series, being stand-alone, it allows itself to really dig into a plot line with consequences the series initial run couldn't pull off to the very end, but the reality is Torchwood always could have been a little braver if it had this similar energy even without constantly threatening the status quo and the main characters.  The politics, tension, and villainy were never precluded by the needs of an ongoing TV series, in my opinion, and this miniseries is a good example of why that is, even as it takes advantage of standing alone and not really having to worry much about the future (as the series even here does feel like it is kind of winding down and is ready to go big and bold).