Across:
8 A vital (a vital) building (= anagram indicator) (a vital = LATVIA) in Eastern Europe (LATVIA),
9 Bodyguard (HENCHMAN) from concert hall (National Concert Hall = -NCH-) embraced by tough guy (HE-MAN) (HENCHMAN),
10 One of those in 15 across similarly (TOGS similar to ‘swimming costume’) with thermal resistance units (TOGS),
11 Time slot if (time slot if) out (= anagram indicator) (time slot if = LEITMOTIFS) of recurrent themes (LEITMOTIFS),
12 Fragment of Thomas Aquinas’s autobiography (fragment of ‘thomas aquiNASS AUtobiography’ = NASSAU) is found in The Bahamas (NASSAU),
14 The outfit’s (the outfits = COSTUMES) closing of 15 across (closing of ‘swimming costume’ = COSTUME-) is top-secret (top ‘Secret’ = -S) (COSTUMES),
15 You might get into this for 24 down (get into SWIMMING COSTUME for a ‘swim’) covering up one of those doing a few strokes (SWIMMING COSTUME),
18 In Review (= reverse indicator), quickly scrutinise (scan = -NACS) for a (-A-) graduate (MA = -MA-) getting to grips with lost (-L-) (ALMANACS) yearbooks? (ALMANACS),
20 Stir up (stir up) trouble (= anagram indicator) (stir up = PURIST) – the traditional type that’s uncompromising (PURIST),
22 Is taking drugs (HIGH) with Jersey (JUMPER) (HIGH JUMPER) sportswoman (HIGH JUMPER),
24 Record (record potato = SPUD) for setting up (= reverse indicator) duty free shops in a roundabout way (‘DUty free shoPS’ in a roundabout way = dups = SPUD),
25 Fellow (F-), in addition (also = ALS-O) takes in first endurance (first ‘Endurance’ = -E-) race (Tourist Trophy race = -TT-) (FALSETTO) and is vocal we hear (FALSETTO),
26 Strange (= anagram indicator) role – it (role it = LOITER) is what you’d expect a lounge lizard to do (LOITER).
Down:
1 A (-A) shadow (dog = -GOD-) agency (Associated Press = AP = PA-) turns over (= reverse indicator) (PAGODA) temple (PAGODA),
2 The days before (EVES) Greaves lost rag (‘Greaves’ lost ‘rag’ = eves = EVES),
3 Mediterranean cheese (HALLOUMI cheese from Cyprus) starter in (starter/first letter ‘In’ = -I) order (-O-) consumed by religious leader (mullah) cutting back (= reverse indicator) (mullah = HALL-UM-) (HALLOUMI),
4 A way of communicating (THAI language) to thespian without using pens? (‘thespian’ without using ‘pens’ = thia = THAI).
5 Uplifting (= reverse indicator) ballad (song = GNO-S) about last letters from Eve (last letters ‘froM evE’ = -ME-) (GNOMES) and figures from The Garden (GNOMES),
6 Athlete (SHOT-PUTTER) fired (SHOT-) by club (-PUTTER golf club) (SHOT-PUTTER),
7 It’s a fair amount of time (half of) for those expecting (half the time for those expecting a child = HALF-TERM) break from school (HALF-TERM),
13 Bordering on sophistry (bordering on ‘SophistrY’ = SY-), head of government (Prime Minister = PM) backed (= reverse indicator) (PM = -MP-) away (-A-) from this (THIS-) response, ultimately (‘responsE’, ultimately = -E) (SYMPATHISE) to offer condolences (SYMPATHISE),
14 Pens (CAGES) produced by Old Bob (old bob = shilling = -S), for example (e.g. = -GE-), with a (-A-) carbon (C-) twist (= reverse indicator) (CAGES),
16 Clip of (e) Willie (Willie) (‘Willie’ without ‘e’ = WILLI-) Wonka heading (‘Wonka’ heading = -W-) for Washington (WA) twisted (= reverse indicator) (WA = -AW) (WILLIWAW) with violent wind! (WILLIWAW),
17 Comparable with (ON PAR-) what you might hear in Spanish bullring (-OLE) (ON PAROLE) when let out subject to conditions (ON PAROLE),
19 Mental sharpness (ACUITY) of American (A-) going to university (-U-) in LA, for one (Los Angeles = city = -C-ITY) (ACUITY),
21 Part of the service (SAUCER) dressing (SAUCE-) royal (-R) (SAUCER),
23 Topsoil – it’s removed (‘topsoil’ ‘its’ removed/without ‘its’ = opol = POOL) by Kitty (kitty/money = POOL),
24 Get overseas (SWIM) phone card (SIM card = S-IM) containing tungsten (tungsten symbol = -W-) (SWIM).