Theme - explicitly stated - 8 down - for those of us not too familiar with them, friendly clues made them deducible or guessable. Solving time, 31 mins.

< = reversed * = anagram

ACROSS

9 T (AU) RUS (t) Au = gold

10 PA V O

13 TEST-F(L)EW Test = international (cricket match). Though it had wider meanings in years gone by - what are now called ‘play-offs’ in football were known as ‘test matches’ in the 1890s before automatic promotion and relegation was introduced.

15 CLAUDE LORRAIN Never heard of him, but pleased to work it out from the wordplay and verify later (ruined a collar)*

17 FAN TA S(I)A SA = sex appeal = it

21 HOROLOGIUM (room oil ugh)*

23 CROW(d) the Latin version of which (Corvus) is an 8 down.

25 NOSE DIVE

DOWN

1 B (LEAR) Y King Lear

4 ST (Street) AS IS

5 MU(sic) TI (it<) A musical conductor.

6 E (U) ROP EAN (nae por(u)e)< u = university pore = study nae = no (Scottish)

8 CO (NSTE) LLATION (sent)* Clued subtly not to be too obvious - I was looking for an anagram of stars at first

14 FRATRICIDE (Terrific ad)*

15 C (YAN) O GEN (any)* co = company gen = information

16 RE (ARM O) ST

18 STOL ID Lots<

20 GROOVY Double definition

22 OM IT cf 17 ac

I always find Enigmatist crosswords difficult, and I’m prepared to accept that may be because of a shortage of horsepower between my ears. But this time I did get there.

Lots of great clues - and I’m struggling to see which of the answers I should leave out - there are no “gimmes” in  this puzzle. 1 down in particular deserves a prize

ACROSS 

9 ROC-K-NROL-L : “cor” in reverse with “k” for king, “lorn” (abandoned) in reverse and “l” for left

10 PLATO(on)

11 DUNG-EON : truly awful pun. Encore !

12 CLUE-DON : “Fellow” as in University “don” .

13 CA(PU)T : A “caput” is “any head or headlike expansion on a structure, as on a bone.” - reference to a CAT scan, with UP reversed

14 MARK-E(TIN)G

16 INSTRUMENT PANEL : (METUNITPLANNERS)*

19 EC(CENT)RIC - CIRCE was the sourceress

21 SQUAW - either SQUAW(l) or SQUAW(k)

22 TRAMMEL - appears backwards in “probLEM MARTin” - it means “to restrain”

23 MERRIER - thanks for the correction linxit - in the saying “merrier”accompanies “more” and we have Perrier swapping the P for an M. If you got MORTIER give yourself half a mark - it’s what I thought it was (i.e sounds like “more tear”. It’s the French word for a mortar board.)

24 X-ENON : i.e NONE in reverse with “X” (ten). “Elementary” in the sense of “being a chemical element” 

26 NAILBRUSH : (RNA BLUISH)

DOWN

1 PREDICTIVE TEXT - the word “made” can become the word “naff” if your mobile phone’s predictive text facility is switched on. Awesome clue.

2 S-CH(N)APPS

3 IN JEST - ho ho. Sounds like “ingest”

4 DOWN MEMORY LANE - (MODERN WOMEN LAY)* - a totally faultless clue - not a word wasted. “Jog” points you towards memory, with “out” being the anagram indicator.  

5 ELECTRONIC MAIL - (TO ME IN CLERICAL)*

6 SP(RUCE)UP - (CURE)* inside PUPS reversed

7 firin(G AND HI)ring

8 JOHN GALS-WORTHY - Cheeky : “John” is a toilet word as is “Throne”. “Gals” are chicks and “worthy” is deserving. He wrote “The Forsythe Saga”

17 RENAMING (?) - It’s certainly to do with assigning a new title … didn’t get the “polls” references - something to do with changing your name by “deed poll” maybe ?

18 N(AU)TILUS - (INSULT)* with AU = French for “to the”. It’s the submarine for Jules Verne’s “Twenty Thousand Leagues Under the Sea”

19 C-RAN-NY - “C” for Clubs is promoted to the top of the word. Big Apple is NY - “managed” is traditionally “ran” in crosswords.

20 S-T(R)OBE - Designate is “to be” e.g the “bride-to-be”   

In a comment a few weeks back, Eimi mentioned that his favourite clue of the year so far was in a forthcoming puzzle by Bannsider. Assuming this is that puzzle, then I’m none the wiser as to what that clue might be because there are at least 3 brilliant clues here (25a, 28a and 8d) and a few others that are top-notch (I’m thinking of 12a and 9d but you may have your own picks).  A great puzzle, and a joy to solve.