Across:
   1. This may have watched as you and I became drug-free (6)
   4. About time plant was put away (4)
   7. Purchase of old hot stew (8)
   8. Local river initially emits noxious waste! (6)
  10. Old king’s edict produces something to eat (8)
  13. Short US 16 takes visitor to see explosive device (6)
  14. Ties up head of hospital in badly-organised retest (7)
  15. Doctor itches to see moral principles (6)
  18. Distinguished holy man may be by cathedral (7)
  19. Puzzle of event being held by backward nations (6)
  20. Bears and cats play outside now with Penny (7)
  25. Smash up patio with energy from drug (6)
  26. Come out again and flip, say, about taking setter to queen (2-6)
  27. Topless seafarer gets time to see cutter (6)
  28. Sag with insolence? (8)
  29. Muted sounds of faint tremulous beginnings (4)
  30. Gazes at drug-taking celebs (6)
Down:
   1. Lowly Oscar is upset and confused! (6)
   2. Wager that chap is inside, bidding (6)
   3. One has empty accommodation on the river, perhaps (6)
   5. Carrier without underwear appears in farce (8)
   6. Struggle a long way to get popular poison (8)
   7. Foolish leader’s law becomes reality! (4)
   9. I stun Duke running to become emperor? (6)
  11. Allow workers’ representatives to start to enter plant for lunch (7)
  12. Where to holiday accompanied by that woman (7)
  13. Talk rubbish about the Spanish clergyman (7)
  16. Guard is in Paris embracing firm redhead (6)
  17. Strange things are tidied so badly! (8)
  18. Icy confrontation is bad news for seafood restaurant (5 3)
  21. Work out law officer’s not heartless nit-picker (6)
  22. Second Rome trip over weekend to get cigarette lighter (6)
  23. Organise search for bridges (6)
  24. Live with officer’s supporter (4)