Cryptic crossword No 2,570

Some great stuff in this although I was defeated by 21a and 2d. 12d and 18d are both brilliant. A couple I put in from crossers and couldn't parse (in reply)

Thanks Rough, as Orinoco says lots to like here, especially 1a, 15a, 21a, 12d and 18d. Some very tough clues: 27d, 2d (for obscurity), 4d, 5d, 22d. Thanks again, PW