Matt Smith, Karen Gillan, Arthur Darvill & Steven Moffat in a battle of wits. Epic hilarity ensues. Quite possibly one of the most adorable thing I've ever seen. I had to watch it twice because of Matt's miming.
:'( River Song's Timeline - If you have any confusion about River's timeline this is the video to watch. Narrated by River herself. "We go way back, that man and me. Just not this far back." It's so much more sad to see it from her angle.