No 12537, Thursday 31 Jan 2019, Dr. X

ACROSS
1   Renegade mafia head caught leaving nation (8) APOSTATE {cAPO}{STATE}
5   Dead snake outside sanctuary (6) ASLEEP {AS{LEE}P}
10 Is ABC perhaps? (5) BASIC &lit
11 Like Lady Macbeth in the act? (3-6) RED-HANDED [CD]
12 Shoot around study and scatter (6,3) SPREAD OUT {SP{READ}OUT}
13 Because of couple’s performance, a little overcrowded (3,2) DUE TO {DUET}{Ov...d}
14 A skin problem? We’d like you to get in touch (6) CALLUS {CALL US}
15 Rushed to fire rifle (7) RANSACK {RAN}{SACK}
18 Massacre! Save songstress (7) BUTCHER {BUT}{CHER}
20 Foolishly dares to trap many snakes (6) ADDERS {AD{D}ERS*}
22 Cold heartless beauty rejects superstar (5) CELEB {C}{BElLE<=}
24 Drunk about to bother inexperienced driver! It makes one see red? (9) TAILLIGHT {T{AIL}{L}IGHT}
25 They reduce tension when sloppy amateur gets involved in rifts (9) RELAXANTS {RE{LAX}{A}NTS}
26 Life-giving source of tincture in ampoule (5) VITAL {VI{Ti...e}AL}
27 Give up unnatural diets involving shakes principally (6) DESIST {DE{Sh...s}IST}
28 Envy move trapping rook say in front (8) BEGRUDGE {B{EG}{R}UDGE}

DOWN
1   Time left for a bit of bowling! Declare, taking the most optimistic view (2,4) AT BEST AT(-t+b)BEST
2   Sharp old boy on retainer (9) OBSERVANT {O}{B}{SERVANT}
3   Fill entire questionnaire to satisfy every requirement (4,3,3,5) TICK ALL THE BOXES [C&DD]
4   They cause one to feel excited! Lots outside run wild (4-3) TURN-ONS {T{RUN*}ONS}
6   Couple of bears: ‘Give us all your money!’ (5,3,7) STAND AND DELIVER {STAND} {AND} {DELIVER}
7   Ignoring start of recession? Brave to invest (5) ENDUE ENDUrE
8   Walks quietly around crop fields (8) PADDOCKS {PAD{DOCK}S}
9   Journalist travelled back to secure appeal (6) EDITOR {ED{IT}OR<=}
16 Entrance into overseas area barred and done away with (9) ABROGATED {ABRO{GATE}aD}
17 Sick boss, not quite restored to health, muddled (8) OBSCURED {BOSs}*{CURED}
19 Stout from large cask in bar (6) ROTUND {RO{TUN}D}
20 A matter under discussion (2,5) AT ISSUE {A}{TISSUE}
21 Remove or tolerate liberal British prime minister (6) ATTLEE ToLErATE*
23 Drunk consuming large pegs finally rises and falls (5) LILTS {LI{L}T}{r..eS}

GRID