A Closer Look at Game of Thrones, Season Four Episode Four

Who are those guys with Jon Snow again? Why is the graffiti in Meereen in English? And what the hell was going on at the end of last night's episode?

Below, as with episodes one, two, and three, I've put together a list of scenes, references, and characters that deserve a special comment or mention. There's no way I got all of the good stuff (and I might be wrong on some of things I've left below)—so please help expand our appendix.