No 11863, Monday 28 Nov 2016, Gridman

ACROSS
1   Organisation in stir? (8) MOVEMENT [DD]
5   Exist with fifty per cent interest (6) BEHALF {BE}{HALF}
10 To throw into disorder is outrageously stupid, with head of residence inside (7) DISRUPT {Re...e} in {STUPID}*
11 One providing cover's knowledgeable and more certain (7) INSURER {IN}{SURER}
12 Tale circulation by saint is most recent (6) LATEST {TALE*}{ST}
13 Sweetheart finds boy at day's end with nothing (8) LADYLOVE {LAD}{daY}{LOVE}
15 Strange way to have right? Wrong (4) AWRY {AW{R}Y*}
16 Holds cashbox immobile (5-5) STOCK-STILL {STOCK-S}{TILL}
18 Brought forth unusual need to have sex (10) ENGENDERED {GENDER} in {NEED}*
20 Excited a girl, old girl (4) AGOG {A}{G}{O}{G}
23 A virtue, it is said, in a card game (8) PATIENCE [DD]
24 Bishop sited uncomfortably in small accommodation (6) BEDSIT {B}{SITED*}
26 Spite poured by the French in letter (7) EPISTLE {SPITE*}{LE}
27 Rice for mother in Indian slum (7) BASMATI {BAS{MA}TI}

28 Followed, quite determined (6) DOGGED [DD]
29 Chief left on first stroke of gong in great haste (8) HEADLONG {HEAD}{L}{ON}{Gong}

DOWN
1   Waist problem Papa studied after a historical period (6-3,6) MIDDLE-AGE SPREAD {MIDDLE-AGE S}{P}{READ}

2   Guest gets rotis served after 6 (7) VISITOR {VI}{ROTIS*}
3   Deer said to be sweet (6) MOUSSE (~moose)

4   Mark, now ten are put together, ignoring final directions (4) NOTE {NOw}{TEn}
6   Writer says site is under construction (8) ESSAYIST*
7   Derived by logic: church official is in First Class (1,6) A PRIORI {PRIOR} in {A1}
8   For king and little boy, illumination around noon is a celestial phenomenon (6,9) FORKED LIGHTNING {FOR}{K}{ED} {LIGHT{N}ING}

9   More elaborate going over one new money manager (9) FINANCIER {F{1}{N}ANCIER}
14 Queer Street possessing character right — an exaggeration (9) STRETCHER {STRET{CH}E*}{R}
17 Disturb a Parisian? Pay up! (8) UNSETTLE {UN}{SETTLE}
19 Underwear's good — putting away without a bit of odour (1-6) G-STRING {G}-{SToRING}
21 Suggest a post to park secret police (7) GESTAPO [T]
22 Having knowledge — in poetry? (6) VERSED [CD]
25 Old Dutch colonist's not wielding right instrument (4) OBOE {O}{BOEr}

GRID