ACROSS
1,5 9’s creation in devious book uncovered culprit here (7,6)
5 See 1 across
10 Associate nips off to confess, incidentally (2,7)
11 The whole lot backed keeping reserves once (5)
12 Record books guarded by uninitiated porter? (5)
13 Muscle in on farm equipment (9)
14 Ground maize or curry? (6,4)
15 Butler maybe goes after cold seafood (4)
17,21 Staggered as case of murder simple for 9’s creation (4,6)
19 Away on vacation, a bird had dreadful time when everything went wrong? (3,4,3)
22 Conductor of opera with name in Italy (9)
23 A small group makes a strong point (5)
25 Reactionary sort’s beginning to become flabby (5)
26 Novel out, she’s a writer, finally? (9)
27 No section was left (6)
28 Constituent of e-reader (7)
DOWN
1 He embodies a German poet? (5)
2 Thought about Edward pocketing deposit (7)
3 Against the current United side following afterthought about Rooney's header (8)
4 Impressive work, mostly well-formed and pointed (14)
6 Apply more than others, presumably, for expenses (6)
7 It can turn either way (7)
8 Fairly poor returns in tax year (9)
9 Somehow one has a great itch to become crime writer (6,8)
14 I am a stubborn sort involving the bill – that can’t be changed (9)
16 A dress fastener previously (8)
18 Airline's given him single fare from Japan (7)
20 Son’s among fairly good ancestry (7)
21 See 17
24 Jack embraces extremely seductive stunner (5)