Unclued lights are connected to a theme word (which does not appear), three in each of three different senses. Two clued lights form an anagram of a name associated with the theme and should be highlighted.
 

Across

8    Gulls escape through a hedge (4)
12    Manager almost cut American scientist (10)
13    Remove stain from tyrant? (6)
15    Nurse holds nail oddly in left hand (8)
18    Revolver on table, inactive at first, put us in hospital (9, two words)
19    Grim sabre wounded something in whale (9)
20    Appeared in incomplete small role (4)
21    Enemy crosses lake, a sheet of ice (4)
24    Soldier beat a gypsy (6)
27    Quickly purchase tin, a bad bargain? (6, two words)
29    Back in the past, Tiberius principally wore this (4)
32    Rector leaves thermostat turned to maximum (9, three words)
34    Like flat space in Europe I would enter free of drugs (9)
37    Gloss girl put round old, cheap stuff (8)
38    Murder victim, adult, hidden by one’s shrubs (7)
39    Sleep with cousin, having a need for baby (6)
40    Forced to repair torn annual (10, hyphened)
41    Squad came together, swinging round area (4)
42    A bore, running into deer in highway incident (8, two words)
 

Down

1    County volunteers on foot with fine, handy weapon (8, hyphened)
2    Strange images of discrimination (6)
3    Good in bed, but get into trouble (5, two words)
4    In pastorship, go wrong making address (14)
5    Organ included in a bishop’s debts (7)
6    One is sadly getting worse medical treatment (8)
7    Generally as a hybrid our pig died (14, three words)
9    Slave from Indies neglected (4)
11    Look adopted by sensible upper-class Londoner (6)
17    Rare wood, black in age (4)
23    Part of circle in punt is a medic (8)
25    Sir Walter’s tip: avoid surgery (4)
28    Offer to pay for short drink, and be ready for orders (7, two words)
31    Result of collapse of currency, with billions invested (6)
33    Locating session away from centre (6)
35    Entranced with absolute rise, having nominal value (5, two words)
 
A first prize of £30 for the first correct solution opened on 6 December. There are two runners-up prizes of £20. (UK solvers can choose to receive the latest edition of the Chambers dictionary instead of cash — ring the word ‘dictionary’.) Entries to: Crossword 2337, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery. Please note the early closing date which is due to Christmas printing schedules.