3939 Novel Connections by Buff

This was a neat puzzle which Gregson enjoyed solving. The extra letters gave the Latin names of four English towns Londinium (London), Lindum (Lincoln), Aquae Sulis (Bath) and Viroconium (Wroxeter). Guessing that London would be in the south-east of the grid, Gregson plotted a line that went north from a letter L. This spelled the word Ermine (Street), the name of the roman road between London and Lincoln. The other roads were Foss Way and Watling (Street). The letters ST were omitted from the word-play in 2 clues to account for the two streets that were omitted. The title was a play on the French word for a novel - Novel Connections could mean Roman Roads.

In the explanations of clues the extra letters are shown in square brackets.

ACROSS
1 Angry dismissal coming home to roost (10)
BACKFIRING b[L]ack (angry) firing=dismissal
10 Those high up on board: oral warning against staff restricting work (10)
FORETOPMEN Fore (warning in golf) T[o] + MEN
12 Lawyer included essence in shortened lease (6)
LEGIST gist in LE[N](D)
13 Crooked players losing head about win (6)
ASLANT (C)AST around LAN[D]
14 Exercises with German radio (8)
TRANSMIT TRA[I]NS + MIT (with in German)
15 Disrupted saner periods (4)
ERAS anag. sa[n]er
16 Sound of shivering -- stress the end of winter (4)
BRRR b[i]rr + R (last letter of winter)
18 Rookies broke rules grasping win (8)
LEARNERS earn (win) in anag. r[u]les
21 Resistance to English perfume -- market again (6)
RESELL R + E + S[M]ELL
23 Fancy topless girl -- that's vulgar (4)
ITCH (b)itch
24 Dutiful behaviour implies getting involved with a touch of tenderness (7)
PIETISM T in anag. imp[L]ies
26 Repeated cry of joy about husband's state (4)
OHIO H (husband) in two cries [i]o + io
28 More insubstantial nest near (6)
AERIER aerie (nest) + [N]r (near)
29 Coryphees (in French) outrageously rude to soprano (8)
DANSEURS dans (French for in) + anag. RU[D]E + S (soprano)
30 Besides English petition includes Latin (4)
ELSE E + L + S[U]E (petition)
32 Couples in harmony, thus abuse retracted (4)
DUOS So [M]UD (rev.)
34 This crossbowman round Cape might have shot albacore (8)
ARBALEST compound anag. arbale (ST omitted from word play) ) + C (cape) + O (round) could make albacore
37 Work shy (6) 2 definitions
EFFORT
38 One who looks unusual front to back (6)
STARER (ST omitted from word play) RARE (unusual) with first letter at the end.
39 One pales having caught infection influxes (10)
AFFLUENCES A (one) + FLU in FENCES (pales)
40 Novices care for garden plot chopping head off plant (10)
TENDERFEET tend + erf + (b)eet

DOWN
1 Table dancing or a strip (4)
BELT anag. t[a]ble
2 Maintain tremolo without first sign of ululation (4)
AVER [q]uaver less U
3 Havana, perhaps with half of Cuba raising flag after independence (5)
CIGAR C[U] + rag (rev.)
4 Petrify one spreading lies after depression (9)
FOSSILISE foss[a] (depression) + I + anag. LIES
5 Before struggle with examination: study! (6)
REVIEW [e]re + vie
6 Obstreperous heartless and intrusive (4)
NOSY noisy less middle letter
7 Almond biscuits, treat distributed amongst friends (8)
AMARETTI anag. treat in AMI[S]
8 Lovers with curves, universal signs of sexual maturity (9)
MENARCHES MEN + ARCHES + [U] (universal)
9 Workers prejudice relegating leader to bottom (4)
ANTS S[L]ANT with S at the end
11 Single floor covering turning up in Asian surroundings (6)
TATAMI I MAT (rev.) in TA[I] & lit.
16 Worries about family (5)
BROOD brood[s] 2 definitions
17 Reheated fare with ultraviolet, chef is sacked (9)
RECHAUFFÉ anag. chef + fare + U[V]
19 Overly fastidious old servant inferior to ideal (9)
ROSEWATER (see SUPERFINE) Rose (paragon/ideal) + WA[I]TER
20 Whack received in harsh arrest (5)
SHARE Hidden harsh ar[r]est
22 By-products following fluorine being included in prepared poisons (8)
SPIN-OFFS F (following) + F (fluorinie) in anag. P[O]ISONS
25 Solved clue about brewed tea, a purified liquid (6)
ELUATE anag. [C]LUE + TEA
27 An order to be executed (6)
ERRAND anag. an [O]rder & lit.
31 Dismal Netherlands has to feel grief of old poet (5)
LERNE [N]L + erne (see YEARN) Maybe an obscure definition since dismal only means swamp in Old US dialect according to Chambers.
32 Indifferent proposal to female (4)
DEAF [I]DEA + F
33 Shudder up north: teacher on drug (4)
GRUE G[U]RU + E
35 Scattered seed endlessly around mid-summer (4)
SEMÉ anag. SEE (D) + [M]M
36 Little Red Riding Hood not comfortable (4)
TROT (nicely hidden definition) TROT-COSY less COSY