Gosh it was an easy one again today and I didn't even spot the theme. I don't think I have the right answer for 19d despite the hints. I suspect I fell into the same trap as Rocky, but haven't yet spotted the escape route. Is the card a playing card? I have T?E ?A?E?.
I'd never heard of the unit in 12ac (despite my science background) or the word in 24ac. It took me a while to place Slade as a prison, though I had no trouble with Ambridge. Despite not spotting the theme (I do hate anything connected to sport) there were a lot of UK related clues. I had to check with my husband if 2d was connected to Rugby, though I spotted the triple definition. But having looked up the parasite, which I'd never heard of, I'm worried that it might have been the cause of my nausea, which came back again this week.
FOI 9ac, LOI 4d (and 19d) CODs 18ac,13ac