The diagram is 13 x 13, normal style, i.e. with black and white squares, and has cyclic symmetry through ninety degrees. Every letter of the alphabet appears at least once in the solution.

ACROSS

  1. Just put a piece of nonsense in the way:
      Perhaps avert a price that’s hard to pay! (11)
  9. One entertaining use of the indefinite article. (7)
10. Bird making noise which sounds like child. (5)
11. Set back a part of the cage. (5)
12. The general’s new plan is elaborate. (7)
13. Top former European group having comeback day. (6)
15. Worker inviting trouble not holding his own. (6)
18. Rushes around for the flower, it seems. (7)
20. Stand tall, as Mickey Mouse wrote. (5)
22. Michael, after he was sacked, managed to make out. (5)
23. King Eugene could return by default. (7)
24. Bad case of mixed corn might open. (11)

DOWN

  2. The ice appears unstable. (5)
  3. To make invalid active it hardly cost a cent. (7)
  4. The nice car deserves a big wave. (6)
  5. Feral animal came from outback to Arthur’s place. (5)
  6. Special extension for holding on. (7)
  7. Wonderful lift given by dry biscuit. (11)
  8. Referee did games around zero: got cold, not wet. (6-5)
14. Covenant north ignored creates change in Chile etc. (7)
16. Mark requesting hearing as listed? The opposite! (7)
17. Holy man needs helpful circle. (6)
19. University treated men time had not honoured. (5)
21. A movement made by fingers and by tails
      On seeing what goes on and off the rails. (5)