The nine unclued lights (including two of two words) form three groups of three: two of the three groups each contain words of a kind; the final group makes up a four-word title. The theme word which links the groups must be highlighted in the final grid. Ignore three accents.
 

Across

 
1    Prepare for playing loud tape (8, three words)
6    Seizes government files (6)
10    Phase one for plugging fantastic drug (12)
14    Note port’s knocked back in parties (7)
15    Witches died among sets of stakes (6)
21    Gape horridly with tiny tongue (8)
23    Whisky’s revolutionary look (6, hyphened)
25    Queen’s behind soft, velvety fabric (5)
26    Snakes almost glide away (5)
29    Abroad, please soldiers with recipe for even more tart (8)
35    Commander collects rupees in Indian city (4)
36    Match detailed by journalist, it’s settled (6)
38    They ogle king leaving naked (7)
41    Tangled line’s extracted that’s caught (6)
42    Lichen blighting Somerset (8, two words)
 

Down

 
1    Heroin’s moved in Indian clubs in the evening? (6)
2    English triumphed over Scots a moment ago (4)
3    Weaken bonnet, say, reversing truck (6)
4    One of Spike M’s Goons gets the willies (6)
5    Learners with a home in the forest? (8)
7    Look over back street in quarters of Glasgow (5)
8    Nice bit of garden where poet’s violet covers meadows (9)
9    Idiots withdrawing cutting remarks in old verses (8)
11    Invalidate appeal to interrupt pit work (8)
13    Bee or wasp keen to cross arable land (8)
18    Drunkenly drive? Any dipso may like it here (8)
20    One who holds back tennis player after a let? (8)
22    Programmes with British actors going in three different directions (8)
24    China arrests right tyrant in city NW of 35 (8)
27    Commanded men to capture queen in action (7)
30    Need information to enter eastern church (6)
31    Eagle, American, not entirely brilliant (6)
32    More than one criminal battles with blades (6)
33    Nurse to race around after dropping ecstasy (5)
37    Stink created by disheartened solvers – editor’s required! (4)
 
A first prize of £30 for the first correct solution opened on 5 August. There are two runners-up prizes of £20 (or, for UK solvers, the latest edition of The Chambers Dictionary — ring the word ‘Dictionary’). Entries to: Crossword 2122, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.