A very enjoyable puzzle from Monk.
Presumably this is the puzzle that appeared erroneously last week in the app…
Monk is a master of misleading. However, as ever, a very tightly composed crossword and completely fairly clued, although a bit of general knowledge is required to complete the grid.
We have a hidden message, and also a pangram!
Many thanks to Monk.

ACROSS
1. Brief, missing target, is prompt to act (5,3,3,4)
QUICK OFF THE MARK
QUICK (brief) + OFF THE MARK (missing target)
9. Take lead from weak bore (5)
EAGRE
[m]EAGRE (weak, take lead from)
10. Cleaners note unopened miscellanea (9)
LAUNDRIES
LA (note) + [s]UNDRIES (miscellanea, unopened)
11. Polish expert gets fish (4,3)
SAND DAB
SAND (polish) + DAB (expert)
12. Deficit regularly ignored after ceremony ruined city (7)
POMPEII
[d]E[f]I[c]I[t] (regularly ignored) after POMP (ceremony)
13. Severe hack involves element of risk (5)
HARSH
HASH (hack) involves R[isk] (element of)
15. Engrossing sex leaves muscle flying round (9)
ABSORBING
(ABS (muscle) + ORB[it]ING (flying round)) (IT (sex) leaves)
18. Latvian fighting vacuous legacy bravely (9)
VALIANTLY
LATIVAN* (*fighting) + L[egac]Y (vacuous)
19. Pan enemy’s swinging blows (5)
HOOKS
HOOK’S (Pan enemy’s)
Referring to Peter Pan
21. Capricious turncoat lodges in Morecambe? (7)
ERRATIC
RAT (turncoat) lodges in ERIC (Morecambe?)
24. Potter perhaps picked up spasms after stroke (7)
BEATRIX
“RICKS” (spasms, “picked up”) after BEAT (stroke)
26. Coin once found on strange island (3,6)
NEW GUINEA
GUINEA (coin once) found on NEW (strange)
27. Judge sends up mischief (5)
JAPES
J (judge) + APES (sends up)
28. Month working in mountains obtains classic French film (5,3,7)
MANON DES SOURCES
M (month) + (ON working) in ANDES (mountains)) + SOURCES (gets)
DOWN
1. Plum, unobtrusive, non-independent school (7)
QUETSCH
QU[i]ET (unobtrusive, non I (independent)) + SCH (school)
2. Usually learner supports popular classes (2,7)
IN GENERAL
L (learner) supports IN (popular) + GENERA (classes)
3. Massage joint, mainly with hands evenly placed (5)
KNEAD
KNE[e] (joint, mainly) with [h]A[n]D[s] (evenly placed)
4. With maximum energy, bull running across line stops swiftly (4-5)
FULL-BLAST
BULL* (*running) across L (line) stops FAST (swiftly)
5. Plod heavily in tango, getting the sulks (5)
THUMP
T (tango) getting HUMP (the sulks)
6. Objective PA campaign upset husband, a heavy sort (9)
ENDOMORPH
END (objective) + PROMO< (PA campaign, <upset) + H (husband)
7. Assistant packs unknown salt (5)
AZIDE
AIDE (assistant) packs Z (unknown)
8. Former US diplomat blowing up on affectionate play (7)
KISSING
KISSING[er] (former US diplomat, blowing RE< (<up, on))
14. Wanting win, bargain hunter engineered complaint (9)
HEARTBURN
(BAR[gain] HUNTER)* (wanting GAIN (win), *engineered)
16. Season, with bay, fresh source of oil (4,5)
SOYA BEANS
17. Is round imaginary circle the same in all directions? (9)
ISOTROPIC
IS + O (round) + TROPIC (imaginary circle)
18. Country native working on motorway (7)
VIETNAM
NATIVE* (*working) on M (motorway)
20. Discriminatory types occur aboard ship (7)
SEXISTS
EXIST (occur) aboard SS (ship, steamship)
22. Wife chops bay tree (5)
ROWAN
W (wife) chops ROAN (bay)
23. Nothing kept in swish boat (5)
CANOE
O (nothing) kept in CANE (swish)
25. Don Juan, saving skin, playing former French province (5)
ANJOU
[d]ON JUA[n]* (saving skin, *playing)
This was the one!
I said it once and I’ll say it again: a lovely puzzle.
1a reminded me obliquely of Aesop’s The Hare and the Tortoise while I enjoyed 28a for reminding me of a favourite writer, Pagnol.
Thanks (again) to Monk and to Oriel.
Regretfully DNF. Convinced 2 Down was INFORMAL, which scuppered 9 Across.
Manon des Sources was very poignant.
Enjoyed it second time round. I missed the hidden message and the pangram so huge thanks to Monk and Oriel.
Missed the nina but spotted the pangram which helped solve the nho AZIDE which could just as easily have been anide or axide for all I knew! VALIANTLY, ERRATIC, MANON DES SOURCES, THUMP and VIETNAM were my favourites. An interesting construction for ANJOU: applying instructions such as ‘deletion of outer letters’ to more than one word is always tricky. I believe it is fair – even though I did struggle a bit, wondering why the outer letters of DoN were being deleted! But I know there are some solvers who feel further indication is necessary.
Thanks Monk and Oriel
Did this last Wednesday, but there’s no proof, because they’ve replaced it with the Basilisk (which I did by annotating a .pdf).
Had to do both again, and completely missed the Nina twice, making me very IRATE (row 10). [But what’s CELON in row 6?]
[Found this on oed.com in the entry for crinkle, n.¹ & adj.: ‘1965 Interest is being shown in a process for providing a boucle-type yarn in
CELON nylon by knitting and deknitting a fabric to provide a crinkle effect. Times 12 January 16/1′]
Thanks M&O
It took me longer than it should have done to realise I had already done this. Diane@1 I wondered about other oblique references to the fables. Was QUETSCH “kvetsch” and alluding to sour grapes? Apparently not. Thanks all.
I did this puzzle last week too. I do not have my notes still, but I do remember enjoying many of the clues. There was some GK I did not have, but it was not excessive. I also remember solving QUETSCH* as my FOI, then immediately seeing QUICK OFF THE MARK. On the other hand, 28ac was my LOI and took for ever.
Thanks Monk and Oriel
*my spell checker refuses to believe QUETSCH is a correct word, by the way
Strange Martyn. It is in Collins
SM@9 It is in the SOED too – it is a word I did not know, and I had to check the SOED after decoding (guessing?) the clue.
Wondered why I was strolling through this then realised I’d done it before. Even for me they’re easier second time round. Missed the pangram until it was too late to be of help & of course the Nina
Thanks both
I didn’t do this puzzle before so I got full enjoyment from it. Quetsch was a new word for me but it fell out of the word play very nicely. Thanks Monk and thank you to Oriel for your usual great blog.
Petert@7: oed.com has QUETSCHY as a 2000s variant of the Yiddish KVETCHY. (I noticed it while looking up the German plums.)
15a ABSORBING – Why not “muscleS“?
I briefly saw this puzzle on line last week but it disappeared before I could start it. Very pleased to see it back – I really enjoyed it.
Lots of favourites including: IN GENERAL, ERRATIC, QUETSCH, VIETNAM, ENDOMORPH
Thanks Monk and Oriel
FrankieG@14 — this discussion has appeared on 15^2 before! It’s because the dics have n (usu. abs) informal an abdominal muscle, and one commenter gave chapter and verse on the Latin nomenclature that contradicted the use of abs=muscles.
Mr Muscle@16, I thought you might’ve meant me on biceps (bicipitis) – a Latin singular clued as “muscles” by Monk …
… AB(dominal) isn’t Latin, [albeit derived from abdomen (abdominis)].
Oed.com has ‘AB n² colloquial (originally Bodybuilding). 1956– An abdominal muscle; = abdominal n. B.3. Usually in plural.’
First sighted: ‘1956 Them judges only sees byes, tryes, pecs and gams—no lats, traps and abs—so nuts to ’em! Muscle Power March 49/2′ …
… However, Wikipedia’s Rectus abdominis muscle page says:
‘… aka the “abdominal muscle” or simply the “abs”, is a pair of segmented skeletal muscle on the ventral aspect of a person’s abdomen (or “midriff”).
That seems to suggest ABS can be singular, too. The Talk page asks ‘One muscle, paired muscle, or two muscles?’ (and 4, 6, 8, 10, or 12-pack?) …
… but I side with User:力 that ‘…there’s a grammatical error in referring to “the abs muscle”.’