Is there a consensus about what the theme actually is? It seems there could be two. The first is suggested by 6d, and supported by embedded names in (1d,16d) and (26a,27a). The second is suggested by 8d ("Nobody expects ...") with embedded names in (1a,4a), (1d,16d), and, coincidentally, the reverse of (26a,27a). The second one suggests that the 8d theme is embodied in the edge clues, but I can't see any embedded names in (7d,19d). I'm guessing the first seems more likely and I'm sure I've missed other thematic answers that would settle it. Or perhaps the theme is people who have tortured us.