Fifteensquared

I found this to be something of a mixture, some very easy and obvious clues and others where the wordplay was convoluted and difficult to parse. The result was that about 20% of the clues accounted for 75% of the solving time.

I have minor quibbles about the definition in 21ac and part of the wordplay in 17dn but apart from that there was nothing untoward (once I had managed to unravel the wordplay in a few clues).

Across
1 LITERACY  T (model) in LIE (piece of fiction) RACY (provocative) – defn. scholarship (scholarly learning)
5 BECALM  BE CALM (told to relax)
10 PARAGON  PA (secretary) *(ORGAN)
11 INSTALL  IN (popular) STALL (stand)
12 MANGA  MAN (fellow) G[oes] A[bout] – a type of adult comic book popular in Japan
13 INTONATED  TO in INNATE (natural) D (daughter)
14 HOVE INTO VIEW  d&cd – according to Chambers and Collins the two equivalent terms are ‘come into view’ and ‘heave in sight’ so this would appear to be a mixture of a part of each. However, COED comes to the rescue with “heave in sight or into view”.
18 CONFECTIONER  *(ENFORCE NOTIC[e])
21 CLOUD BASE  CLOUD (blanket) BASE (support) – blanket and cloud are synonyms when used as a verb but the definition ‘low level cover’ is a little weak. Chambers defines ‘cloud base’ as “the undersurface of a cloud or clouds; the height of this above sea level”. COED gives “the level or altitude of the lowest part of a general mass of clouds”. As the undersurface of a cloud can be anything up to 60,000ft (18,000m) above sea level this could hardly be classed as low.
23 AMAZE  A MAZE (a puzzle)
24 ETERNAL  TER (territory) in LANE reversed (way back)
25 SHINDIG  HINDI (foreign language) in S[trasbour]G
26 METIER  *(TIME) ER (a royal)
27 ENCEINTE  EN (measure) I (one) in CENT (money) E (note) – defn. ‘in the club’ (pregnant)

Down
1 LIPOMA  PO (flower, river) in LIMA (South American city)
2 THRONE  homophone of ‘thrown’ (was flustered) – john and throne are both informal terms for a lavatory
3 RIGMAROLE  RIG (misrepresent) MA ROLE (mother’s character)
4 CONFIDENTIALLY  I in CONFIDENT (assertive) ALLY (colleague)
6 EOSIN  *(INSO[l]E)
7 ABATTOIR  A BAT (a cricketer) TO IR (old government department, Inland Revenue)
8 MELTDOWN  d&cd
9 LISTEN TO REASON  *(INTOLERANT [b]O[s]SES)
15 OPERATIVE  dd
16 ICE CREAM  *(A RECCE I’M)
17 INDOLENT  DOLE (welfare) in IN (popular) NT (book) – the New Testament is surely a collection of books rather than a single book. Both Chambers and COED define it as “the second part of the Bible”.
19 WARDEN  *(Andrew) – one for our regular Guardian blogger!
20 LEAGUE  dd
22 DENSE  hidden in ‘garDEN SEtting’