River: 'This is the day he finds out who I am.'Tonight's episode was a mid-season finale, which is something of a first for us here in the UK, as our seasons are seldom long enough to cut in two. As such, despite answering some of our questions, it left most of the main plot threads hanging. We now know who River Song is, but the central mystery remains tantalisingly incoherent. Emotionally, tonight's episode had some effective set pieces, but I'm going to start off with what I didn't like. There weren't many things, so bear with me.
