GURNEY provides this Bank Holiday Monday's puzzle…
An enjoyable solve with some nice surfaces. 18a was new to me, as was the fairy in 14d.
Thanks GURNEY!

ACROSS
1. Row about doctor’s shouted warning (6)
TIMBER
TIER (row) about MB (doctor)
4. Scarf in exotic kasbah bus, last to leave (8)
BABUSHKA
(KASBAH BU[s] (last to leave))* (*exotic)
10. Detailed check about old copy, that may be listened to (9)
AUDIOTAPE
AUDIT (detailed check) about O (old) + APE (copy)
11. Crew had meal it sounds like (5)
EIGHT
"ate" = EIGHT (had meal, "it sounds like")
12. Italian smoker before suffering setback (4)
ETNA
(ANTE)< (before, <suffering setback)
13. Hostile to work sent round by college officer on other side of globe (10)
ANTIPODEAN
ANTI (hostile to) + (OP)< (work, <sent round) by DEAN (college officer)
15. Imposing figure surely? Not half! (7)
STATELY
STAT (figure) + [sur]ELY (not half)
16. Looking up for this worker? (6)
ROOFER
18. Rock, pleasant to hear (6)
GNEISS
"nice" = GNEISS (pleasant, "to hear")
20. One in authority in Rome’s distinctive group — extremely utopian, that is taken in (7)
TRIBUNE
TRIBE (distinctive group), U[topia]N (extremely) that is taken in
22. Lawsuit involving United, reheard, oddly abandoned, one’s lots to talk about! (10)
AUCTIONEER
ACTION (lawsuit) involving U (united) + [r]E[h]E[a]R[d] (oddly abandoned)
23. 3 Peer ahead of time? Not quite (4)
EARL
EARL[y] (ahead of time, not quite)
25. 5 Moment about right for animal’s simple feat (5)
TRICK
TICK (moment) about R (right)
26. With much to say, story about king at four? (9)
TALKATIVE
TALE (story) about (K (king) + AT + IV (four))
27. 7 Gates initially confronted by appalling tragedy: these devices (8)
GADGETRY
G[ates] (initially) confronted by (TRAGEDY)* (*appalling)
28. Picked up type of ring for youngster on the water (6)
CYGNET
"signet" = CYGNET (type of ring, "picked up")
DOWN
1. Cross note about partygoers (8)
TRAVERSE
TE (note) about RAVERS (partygoers)
2. Painting Midland canon had possibly? (7,3,5)
MADONNA AND CHILD
(MIDLAND CANON HAD)* (*possibly)
3. God ultimately the answer to distress (4)
EROS
[th]E [answe]R [t]O [distres]S (ultimately)
5. Studio area, elite, revamped at end of summer (7)
ATELIER
A (area) + (ELITE)* (*revamped) at [summe]R (end of)
6. Not worth investing in — working capital upfront initially and no income (10)
UNECONOMIC
(C[apital] U[pfront] (initially) and NO INCOME)* (*working)
7. Elated before long time having 100 entered for run that’s instructional? (6,9)
HIGHER EDUCATION
HIGH (elated) + ERE (before long) + DURATION (time, having C (100) entered for R (run))
8. Interim work in theatre (6)
ACTING
9. Self-confident relation in jalopy on vacation (6)
JAUNTY
AUNT (relation) in J[alop]Y (on vacation)
14. Fairy signal over the French plant (10)
PERIWINKLE
PERI (fairy) + WINK (signal) over LE (the, French)
17. Determined he will be next, old having been ditched (4-4)
HELL-BENT
HE'LL (he will) + BE N[ex]T (EX (old) having been ditched)
19. Politician on return thanks probing Spanish fellow (7)
SENATOR
(TA)< (thanks, <on return) probing SENOR (Spanish fellow)
20. Singer’s collection of trophies maybe (6)
TREBLE
Double (cryptic) definition
Referring to the winning of three trophies in a season
21. Badly-organised painter getting trouble and grief from start (6)
RAGTAG
RA (painter) + G[etting] T[rouble] A[nd] G[rief] (from the start)
24. Vote against overrides introduction of vast fighting force (4)
NAVY
NAY (vote against) overrides V[ast] (introduction of)
Thanks Gurney and Teacow!
A minor observation:
HIGHER EDUCATION
Def: That’s instructional?
before=ERE and long time=DURATION (I am not sure but Chambers gives
‘Time indefinitely’ as a meaning under ‘duration’).
Agree with KVa@1 on HIGHER EDUCATION.
For DURATION oed,com has ‘1.d. 1916– The time during which a war lasts, used first of the 1914–18 war from the term of enlistment ‘for four years or the duration of the war’; esp. in for the duration, until the end of the war; hence, for a long or an unconscionably long time. Also attributive.’
Thanks G&T
Enjoyed this but could not parse “treble” for either definition. Also, I was hesitant about “babushka” which I understand as “grandma” (as does Google). Why is “trick” an “animal’s simple feat” ?: not just “simple feat”.
John@3
TRICK
It could mean ‘a simple feat learned by an animal or a person’ according to Collins.
Thanks for the blog, good set of neat clues.
BABUSHKA head-scarves having a bit of a moment in solidarity with Ukraine.
I also wondered about animal’s for TRICK, apparently this is a bit of a thing on the internet and also has a TV show.
I was thinking 25a was to do with a one trick pony
Liked this, “Gneiss” was LOI, had some trouble parsing the longer clues, but all doubts cleared here. Thanks to Teacow and to Gurney for the puzzle.
Enjoyable and not too taxing for a bank holiday. We couldn’t parse 7dn properly, as we thought the long time was ‘eon’; otherwise no problems. We knew GNEISS as one of us needed a rudimentary knowledge of geology professionally at one time. Interestingly, Chambers gives the headscarf meaning of BABUSHKA as ‘chiefly US” before the original ‘grandmother’ or simply ‘old woman’.
Thanks, Gurney and Teacow.
Many thanks to Teacow for the excellent blog and many thanks also to all who commented.
Enjoyed this, altho didn’t get the full picture on 10ac I had O TAPE as the old copy n became overexcited n bunged Audi in without worrying.. nice picture anagram, and Gneiss has to be one of the old chestnut variety of rocks.. Babushka being a scarf makes sense as the old Russian grandmas all seem to wear them, certainly in doll form, but I do recall Kate Bush’s video didn’t feature many elderly Russian peasant women. I too was confused by the animal in 25ac and felt the the Magic Circle might have something to say on the subject, although on reflection they probably call what they do an illusion.. don’t think I know the fairy but amazingly am familiar with the flower!!
Good stuff
Thanks Gurney n Teacow
Generally enjoyed this one which was a speedy solve until towards the end when I got held up by roofer and a couple of others. Thank you for visiting Gurney. I always like it when the setter appears here.