2183: Group theory

Each of 31 clues comprises a definition and a hidden consecutive jumble of the answer including one extra letter; the extras spell five words of a quotation in ODQ. The quotation’s next three words, identifying two groups, form an unclued light. Remaining clues are of the same type, but without extra letters in the jumbles; initial letters of these clues spell the author’s surname, which is an unclued light. Three unclued lights belong to one of the groups, and three unclued lights (one of which consists of two words) belong to the other.

Across

9    Depict broken home (4)
11    Fruit seller chops up dates (10)
12    Seaweed filling area (4)
14    Tour bus amid Italian region (6)
18    Pursue a thin rodent (5)
20    Bent appendage like a wing (7)
21    Defeat messenger considers (7)
23    Poisonous gas minister bans (7)
27    Quantum number drops in size (7)
30    Cardboard figure treated as novelty (7)
32    City had rejected government by two (7)
36    Scribe likes college (5)
37    Seek out rural place in Finland (5)
38    Disclose tunnel vision (6)
40    Uniform is tame and conventional (10)
41    Logician taken on voyage (4)

Down

1    Lower views of cliffs (5)
2    Immense heat in greenhouse (5)
3    Cavalryman launches appeal (6)
4    King dreads hunger (5)
5    Demand tip, using shovel (7)
6    Film on craft of Latin origin (7)
7    Exceptional arches of nostrils (6)
8    Possibly see strap round roll of fat (9, two words)
10    Newspaper sent ironic introduction again (11)
13    Lozenge-shaped brooch mislaid (7)
15    Rope artisan put in belfry (8)
16    Game hunter liking protein (11)
19    Entertainers create headlines (8)
21    Assess mixed European openings (9)
22    Herbs wretches scatter (7)
26    Follower of philosopher talks to scientist (7)
28    Work by singer originating in heaven (7)
31    Respiratory condition batsman hid (6)
33    Type of lamp bracket, gilded (5)
34    Thorny problem ordained (5)

A first prize of £30 for the first correct solution opened on 27 October.