Across:
   1.  First time, first day: London transport is back! (5)
   4.  Did free bail deter criminal? (9)
   9. 10, ironically (3 2 3 3 4)
  10. Rare low-down abomination! (5 3 3)
  11. Thus the West follows to make work for the reaper (3)
  12. Singer made boy wonder (5)
  14. Umpire's new art - comes back with something you can stick (8)
  17. Bills sell in black market back around top of Angus Road (8)
  19. Leader - elected, perhaps (5)
  21. Letters to the fallen? (3)
  22,25. Words for 10 often impressed (3 5 3 3 12)
  26. Feel bitter about containing almost total physical desire when getting stronger (9)
  27. Keen, astute; but odd absences occur (5)
Down:
   1. To hell with Penny, possessed child! (8)
   2. Sounds like one of the Beatles was a dull chap? (5)
   3. Well - such paths do trend well! (7)
   4. Castle ran out of transport for bombs (9)
   5. Letter delivered by radio - well done! (5)
   6. The high ones have lots of money and flash cars (7)
   7. Passing train sent off the rails (9)
   8. Repudiate racket surrounding 11 (6)
  13. Big hits are popular when performed in these arenas (9)
  15. Drab suits stitched up for believing in no greater purpose (9)
  16. Government ran central housing admission process (8)
  18. Make it react to having more spite (7)
  19. Calm half of 17 took dinner (7)
  20. Quietly pass on favour (6)
  23. Sex, I learnt, can give one an unwelcome character (5)
  24. Wrist-slapping legal orders? (5)