No 12656, Wednesday 19 Jun 2019, Afterdark

ACROSS
1   Exploration in Bay of Bengal, say to collect reading on source of crustacean hatchlings (6) SEARCH {SEA}{R}{Cr...n}{Ha...s}
4   Eardrops (to save money) used in part of the eye (6) RETINA {EAR}* over {TIN}
9   Starch is created by gas reflux only (4) SAGO {GAS<=}{O}
10 Houses are ready, drawing people in leading to loans eventually (10) APARTMENTS {A}PART{MEN}{To}{l..nS} Anno not clear (Addendum - {AP{ART}{MEN}T}{l..nS} - See comments)
11 Show signs of changing sides on request (6) APPEAL APPEA(-r+l)L
12 Notice doctor's work with society providing medicine... (8) EARDROPS {EAR}{DR}{OP}{S}
13 ... making news outside of India (9) FORMATION FORMAT{I}ON Anno pending (Addendum - inFORMATION - See comments)
15 Country's cognizance by law should be even (5) KENYA {KEN}{bY+lAw}

16 Take over America; USSR heartless on gaining power (5) USURP {US}{UssR}{P}
18 Static, yet mobile in Singapore, say (4,5) CITY STATE*
22 Place in Chennai's best to retire in country (8) MALAYSIA {MA{LAY}S}{A1<=}
23 Even though criminal, risk capturing India (6) ALBEIT {AL}{BE{I}T}
25 Perhaps, Indian cricket team is second class, only busy in some way to earn money at England (4,2,4) BOYS IN BLUE {B}{O}{BUSY+IN}* over {L} and {E}
26 Works on alliances after losing power (4) ACTS pACTS
27 Suggest book to study first before entrance exam (6) DENOTE {DEN}{OT}{Exam}
28 A despot has elections rigged eventually at the source to gain support (6) ADHERE Acrostic

DOWN
1   Used a politician to earn orders for cleaner (7) SHAMPOO {SH}{A}{MP}{O}{O}
2   Rose is one with good energy (5) AWOKE {A}{W}{OK}{E}
3   Church and State agree to crown, say (7) CHAPLET {CH}{AP}{LET}
5   Woman goes weak after last course in restaurant (6) EATERY {c...sE}{wATERY}
6   Determined to school trainees to pass final examination (2,7) IN EARNEST {TRAINEES}* over {e...oN}
7   Perhaps a stiff test for Australia to overwhelm the best, with Yuvraj at one end (7) AUTOPSY {AU}{TOPS}{Yu...j} (Addendum - {AU{TOP}S}{Yu...j} - See comments)
8   Without doubt, Tom's self-esteem's strong, almost everyone finds at the very end (13) CATEGORICALLY {CAT}{EGO}{RICh}{ALL}{verY}
14 Murder, perhaps isn't moral (6,3) MORTAL SIN*
17 Does a foe stop short cooking fish? (7) SEAFOOD {DOES+A+FOe}*
19 Yes, closed early and took break on 31st December (4-3) YEAR-END {YEs}{A}{REND} (Addendum - {YEAh}{REND} - See comments)
20 A plant whittles badly when water source is absent (7) THISTLE wHITTLES*
21 You hear teens are upset with precursor of world wide web (6) USENET (~you){U}{TEENS}*
24 Criticism of boy’s flimsy (5) BLAME {B}{LAME}

Reference List
Reading = R, Only = O, Are = A, Society = S, India = I, Chennai = MAS, Power = P, Criminal = AL,  Only = O, Money = L, England = E,  Used = Second Hand = SH, Order = O, With = W, Energy = E, Church = CH, Women = W, Boy = B

GRID