Left-looking organization

Plaintext grid

Across
7. Fly comes flying around place near North Carolina, showing certain smugness (4-11)
9. ISIS fighters maybe capture one town’s leader and, among others, foremost loyal people holding on to land rights (15)
10. Pharmacy can offend extremists… and may finally send help to sister’s disease (15)
13. For each hotel retreat, resort with baths, maybe (7)
15. Marx’s Capital, in Oxford University collection, held at first in possession of left-looking organization (7)
16. One-time occupation of someone who cries after Crosby sings, passing by (8,7)
19. Colonel brought in to mark readers and hobbyists (5,10)
21. "Oddly, forest covers minion, decapitated by Native American king", describes historical novel (10,5)

Down
1. Messengers are prettier, sweetly modified (15)
2. Carbon-free binding agent supporting a very strong farm house is releasing (15)
3. Work times for Carmen and Don Carlos? (6)
4. Info in Russian? Yes, thank you (4)
5. "I record a remix of rhymes on the outside, taking no heroin" – part of it’s true (15)
6. Breed of twisted terrorist ethics (8,7)
8. Replacement of depot chosen (5)
11/12. Morrissey’s holding back agreement with superior (3,3)
14. 19 across left out lists, late to make letter (3)
15. Boasting of depression turning around (3)
17. Retired criminal seen by road leading to city in Ireland (6)
18. Countering bias around the start of election, for some time (5)
20. Company imports Ohio salmon (4)