I've been out all day and started very late. I've only got a few and have to decide whether to persevere or continue watching The Bridge (I'd forgotten how good it is). I don't know the theme and am too tired to google as I'm not sure what to google. I may start agin tomorrow, but can I have a hint for 13ac and 22ac. That may help me get started.
Unfortunately, I proved too tired to think and went to bed at 2.00am with little progress. I seem to have woken up this morning just as tired. But at least I have the theme now. Are all the themed clues identified by the single letter? Are all the themed answers in one country?