Across:
8 Unreal (unreal) novel (= anagram indicator) (unreal = NEURAL) dealing with the nerves (NEURAL)
9 Rung for dinner (BELL-) dances (-HOPS) (BELLHOPS) with American porters (BELLHOPS),
10 American city (Miami) going most (i) of the way back (= reverse indicator) (‘Miami’ without ‘i’ = miam = MAIM) put out of action (MAIM),
11 Criminal (= anagram indicator) route (route = -UERTO) taken to a fair amount of (half of) riches (half of ‘RIChes’ = RIC-) in River (River Po = P- -O) (PUERTO RICO) Island (PUERTO RICO),
12 State (ALASKA) of a (A-) petition (-ASK-) in American city (LA = -L-A) (ALASKA),
14 One picking up loads (FORKLIFT) from short (e) biography (life) (‘life’ without ‘e’ = -LIF-) after (= position indicator) weekend (‘weeK’ end = -K-) in private space? (fort = FOR-T) (FORKLIFT),
15 Get better (HEAL-) skin and bones (thin = -TH IN-) from sun, care (sun care) sport (= anagram indicator) (sun care = -SURANCE) (HEALTH INSURANCE) and sick pay that comes at a premium (HEALTH INSURANCE),
18 Outline (DESCRIBE) of first dictionary (first ‘Dictionary’ = D-) by English (-E-) writer (-SCRIBE) (DESCRIBE),
20 Work too hard (OVERDO) for one of those in charge of The Party perhaps (OVER DO),
22 Knock (-HIT-) one (one) back (= reverse indicator) (one = -E NO-) in discerning (wise = W-ISE) (WHITE NOISE) frequency that one associates with a fan (WHITE NOISE),
24 Crafty type (HULL) on both sides of hundred-dollar bill (on both sides of ‘HUndred-dollar biLL’ = HULL),
25 Obsessively indecent type (PRURIENT) has a job in marketing department (PR-) getting youth centre (‘yoUth’ centre = -U-) to find bearings (orient) heading off (o) (‘orient’ without ‘o’ = -RIENT) (PRURIENT),
26 Some deliver a service (Some ‘delivER A SERvice’ = ERASER) that’s used to clean-up childish errors (ERASER).
Down:
1 Feature (DETAIL) of island (-I-) in meandering (= anagram indicator) Delta (delta = DETA-L) (DETAIL),
2 Street car (TRAM) going around traffic jam (going around ‘TRaffic jAM’ = TRAM),
3 Careless (SLAPDASH) friends (pals) holding up (= reversal indicator) (pals = SLAP-) Dart (dart = -DASH) (SLAPDASH),
4 King of the Road (hobo) needs no introduction (h) (‘hobo’ without ‘h’ = OBO-) – at The Point (East = -E) (OBOE) it’s played by musician (OBOE),
5 Cup broken off sculpture (‘cup’ broken off /from ‘sculpture’ = slture = ULSTER) in one of the four green fields (ULSTER),
6 Presumably this is what Noah’s staff took as a crafty diversion (SHORE LEAVE) to stay out of the water? (SHORE LEAVE),
7 Particular (SPECIFIC) epics (epics) adapted (= anagram indicator) (epics = SPECI-) by figurehead (‘Figure’ head = -F-) in charge (in charge = -IC) (SPECIFIC),
13 Petition (SOLICT-) ROS (ROS) working (= anagram indicator) (ROS =-ORS) (SOLICTORS) for a number of barmen (SOLICITORS),
14 Cross Swords (cross swords in fencing = FENCE) by going around the border (FENCE goes around border of property, for instance),
16 Person getting a sight better (optician) asked me to look at this? (EYE CHART) If you get to view it, you’re probably seeing things! (EYE CHART),
17 Locked (UNOPENED) university (U-) putting out (broadcasting = on) review (= reverse indicator) (on = -NO-) by couple of writers (pen + ed = -PENED) (UNOPENED),
19 Poor (IN NEED), unrefined, discarded fur (‘unrefined’, discarded/without ‘fur’ = neined = IN NEED),
21 Party (DO-) workers (-MEN-) following (= position indicator) extreme political (extreme ‘political’ = -L-) (DOLMEN) plot that’s deadly (DOLMEN tomb),
23 Tiny bit (IOTA) stuffed into sliotar (stuffed into ‘slIOTAr’ = IOTA),
24 Moth-eaten Monet is left out (‘moth-eaten’ Monet is left out/without ‘Monet’ = heat = HEAT) in the hot weather (HEAT).