Across
8. Bit of "Code Green" arranged when king gone (4)
9. Sort of mean Christmas: I set off with no seconds at all! (10)
10. Going up? Indicator is in 21! (6)
11. Silly tiny life not going on forever (8)
13. After some time without food, Magritte returns for nut perhaps (8)
14. Mistakes rose badly handling larger car (6)
16. Mistily developed unknown removed, as concept vital to calculus (6)
17. Irritation on genital surface is a problem (6)
18. Texts about securing roughly 2.72 in 6 (6)
20. Vital part of returning scholar: get nitpicking! (8)
21. Problematic trading involving future close and how rapidly it's going up (8)
23. King wearing silly gowns... having two of them doesn't make it right (6)
24. Reserved about a thousand plus... wrong, or necessary? (10)
26. Requirement one educated to maintain (4)