No 12125, Friday 29 Sep 2017, Arden

ACROSS
1   Should be given death sentence – get off high horse (7) MUSTANG {MUST}{hANG}

5   Bishop broke rule perhaps – contracted the French disease (7) RUBELLA {RU{B}EL*}{LA}
9   Stoned, exhausted (5) JADED [DD]
10 Edition on communist movement (9) REDACTION {RED}{ACTION}
11 Vehicle with insurance – you finally enter the city (9) VANCOUVER {VAN}{CO{yoU}VER}
12 Bard's golden enclave (5) AUDEN {AU}{DEN}
13 Final scene by girl in Tempest (4) GALE {GAL}{s..nE}
15 Initial delivery receipt misplaced infirm (8) DECREPIT {De...y}{RECEIPT*}
18 Disease treated, physiologist to go away (8) SYPHILIS PHYSIoLogISt*
19 Drink up some of the potion (4) TOPE [T<=]
22 In Africa primates are found on this island (5) CAPRI [T]
24 Live in more modest accommodation, it doesn't matter (5,4) SMALL BEER {BE} in {SMALLER}
26 Serenade opponent briefly in rocking chair (9) CHARIVARI {RIVAl} in {CHAIR}*
27 Associate that's canned (3-2) TIE-IN {IE} in {TIN}
28 Bidding system yet to be perfected by novice (7) ACOLYTE {ACOL}{YET*}
29 He knows about costing (7) GNOSTIC*

DOWN
1   Desert transport, Germans agree to hop in (6) MOJAVE {MO{JA}VE}
2   Depression in the ocean – underline there's no activity (9) SEDENTARY {SE{DENT}A}{RY}
3   Car's old, makes noise (5) AUDIO {AUDI}{O}
4   Aim to check off drive? He's written volumes (4,5) GORE VIDAL {DRIVE}* in {GOAL}
5   Tracker tracks up and down (5) RADAR [CD] (Correction - <=> - See comments)
6   Lost everything, reach out, infused capital (9) BUCHAREST {BU{REACH*}ST}
7   Landowner raises money in foreign currencies (5) LAIRD {D}{RIAL}<=
8   A side gets new cover (6) AWNING {A}{W{N}ING}
14 A social group in the troubled metropolis (9) ETHNICITY {IN+THE}*{CITY}
16 Cover over heel coming down (9) CASCADING {CAS{CAD}ING}
17 Tool put in place (9) IMPLEMENT [DD]
20 Starts acting crafty again, spies hide behind tree (6) ACACIA {Ac...g}{Cr...y}{Ag..n}{CIA}

21 Metal discs regularly go missing, it's strange (6) IRONIC {IRON}{dIsCs}
23 Philosopher extremely peaceful at Oxford (5) PLATO {Ph...eR}{AT}{O}
24 Old? Makes least difference (5) STALE*
25 There's much to gain if you win it (5) LOTTO {LOT}{TO} &lit

GRID