Previous quick solution

Across: 1. Gulf 8. Alteration 9. Pentacle 10. Exit 12. At odds

14. Enigma 15. Prompt 17. Mighty 18. Adze 19. Infantry

21. Impenitent 22. Sell

Down: 2. Unlettered 3. Fast 4. Stacks 5. Grieve 6. Steeping

7. Knot 11. Immaterial 13. Dampened 16. Trivia 17. Miffed

18. Aria 20. Nuts

Fill the grid so that every column, every row and 3x3 box contains the digits 1 to 9.