Across:
8 Ain't leaving stationers ('aint' leaving the 'stationers' = stoers = STORES) or stockholders? (STORES),
9 Prized (ESTEEMED) uplifting (= reverse indicator) encounters (meets = -STEEM-) in river in Cavan (River Dee = E-ED) (ESTEEMED),
10 Behind the scenes around the fringes (‘BEhind the scenES’ around the edges = BEES) working on the production for The Queen (BEES),
11 Those working for Dictator (TYPING POOL) using computers to put out characters, for instance (TYPING), from revolutionary (= reverse indicator) circle (loop = POOL) (TYPING POOL),
12 Pre-election promise (TAX CUT) to charge (TAX) Nick (nick = CUT) (TAX CUT),
14 Plain (ORDINARY) and simple? (ORDINARY),
15 They go shopping for those taking goods (STORE DETECTIVES) from 8 across mostly (‘stores’ mostly = STORE-) to mistakenly (= anagram indicator) test device (test device = DETECTIVES) (STORE DETECTIVES),
18 If recent (if recent) adaptation (= anagram indicator) (if recent = FRENETIC) is Fast and Furious? (FRENETIC),
20 Humble (MODEST) Methodists don’t have this (‘Methodists’ don’t have ‘this’ = meodts = MODEST),
22 Nothing (-O-) in box (carton = CARTO-N-) is (-IS-) is going to open tradesman’s (opening ‘Tradesman’s’ = -T) (CARTOONIST) drawer (drawer/illustrator = CARTOONIST)
24 Connects (links) reports (= homophone indicator) (‘links’ = ‘LYNX’) of big cat (LYNX),
25 It’s a reminder (memory) almost (y) (‘memory’ without ‘y’ = MEMOR-) to one (-I-) leader of the mob (Al Capone = -AL) (MEMORIAL) in The Cenotaph (MEMORIAL),
26 It’s difficult to figure out (RIDDLE) what this might be (this clue is a RIDDLE).
Down:
1 A wise woman (ATHENA) back in the day (-THEN-) in teetotal organisation (AA = A-A) (ATHENA),
2 Blooms in spring (IRIS), in a manner of speaking (Irish), briefly (h) (‘Irish’ without ‘h’ = IRIS),
3 Is in accordance with what’s been said (AS STATED) by a (A-) small (-S-) country (STATE-) close to Ireland (close/end to ‘irelanD’ = -D) (AS STATED)
4 Operated without rota (‘operated’ without ‘rota’ = peed = DEEP) – how profound is that? (DEEP),
5 Doesn’t (doesn’t) disturb (= anagram indicator) (doesn’t = STONED) those on drugs (STONED),
6 Castle (KEEP) popular (IN) with wits? (MIND) (KEEP IN MIND) Retain! (KEEP IN MIND),
7 Staff (RESOURCE) facility? (RESOURCE),
13 Half the body of Latin speakers (half of ‘CORpus’ = COR-) around (-O-) for US (-NATION) (CORONATION) inauguration (CORONATION),
14 Tricky (= anagram indicator) topic (topic = OPTIC) for one employed in the pub (OPTIC),
16 The odd t-shirt (the odd letters in ‘TsHiRt’ = THR-) packed away (-EATEN) (THREATEN) by menace (THREATEN),
17 The dead centre (CEMETERY) of a lifeless place of late (CEMETERY),
19 Adopted (TOOK IN) by Rose (stood) at The Centre (‘sTOOd’ at the centre = TOO-) joining family (kin = -K IN) (TOOK IN),
21 Only one (SINGLE) hour (h) from Pebble Beach (‘sHingle’ without ‘h’ = SINGLE),
23 It’s not working (IDLE) for those characters upset (= reverse indicator) in Channel dispute (those characters in ‘channEL DIspute’ = eldi = IDLE),
24 Party game (LUDO) for loud (loud) drunk (= anagram indicator) (loud = LUDO).