Prize puzzle from the Weekend FT of February 20
The top-left corner of this puzzle took me a while.  I especially like 21D.
Across
1. HECUBA – HE-CUB (young male) + A (a)
4. AVE MARIA – A (a) + V (verse) + ME backwards + ARIA (song)
9. TETHYS – THY (solver’s) in SET (group) backwards
10. TRANSACT – T (time) + RANSAC[k] (search thoroughly, king missing) + T (time)
12. ATHENIAN – HEN (bird) + I (one) both in A TAN (effect of a holiday in the sun)
15, 16, 13, 23. KEEP THEMSELVES TO THEMSELVES – KEEP (look back) + THE (the) + MS (text) + EL (the Spanish) + VEST (cover) + OT (books) + HEMS (borders) + ELVES (fairies)
20. HEAT – HE (man) + A (a) + T (T)
25. BULLETIN – homophone (“bully”) + TIN (canned)
27. ACTIVITY – A (one) + CT (caught) + IT (it) in IVY (creeper)
28. IMPALA – IMP (devil) + A LA (in the style of)
29. KING LEAR – KIN (family) + L (50) in GEAR (items)
30. EXTEND – EX (old) + TEND (nurse)
Down
1. HATRACK – [marc]H + A (a) + TRACK (course)
2. CATCHMENT – CAT (queen maybe) + HM (queen) in CENT (a hundred)
3, 19a. BUY ONE GET ONE FREE – anagram of GREEN BEEF YOU NOTE
5. VERB – BREV[iary] (half of holy book) backwards
6. MANPOWER – anagram of POEM WARN
7. REACH – double definition
8. ARTEMIS – ART (painting) + ME (setter) backwards  + IS (is)
11. DASH OFF – DASH (bribe) + OFF (not available).  Cinephile is very good at clues of this type!
14. IMPETUS – IM (setter’s) + PET (favourite) + US (American)
17. VIENTIANE – anagram of IN E[ast] + NATIVE
18. INTERVAL – [w]INTER (season) + VAL[e] (greetings)
19. GOSHAWK – G (good) + SHAW (playwright) in OK (all right)
21. TYNWALD – TYN[e] (British river, not East) + WALD (German forest).  The Tynwald is the Isle of Man’s parliament.
22. CLIMAX – homophone (“climb axe”)
24. LATIN – hidden word.  Do we take “in” as a hidden containment indicator (as in “in flating”) or is there simply not one?
26. STOA – STOA[t] (Manx mammal).  Is “Manx” in this context a standard crossword-puzzle indicator for a missing tail that we just have to accept?  If so, it is one I do not recall coming across before.  And if not then I think it is an insupportable mechanism that I will vehemently argue against.
some very nice clues here.
25ac made me laugh along with 20ac and 5dn, many not knowing the book of Proverbs
may of struggled a bit. However being a Christian I really liked enjoyed the clue.
Thanks for the blog Pete.
Thanks, Pete, for the blog.
I thought, a very good crossword from The Rev.
It occurs to me that Cinephiles are usually more precise than Araucarias (though some people think these A’s are The Best Of The Best), and I must say I like that.
Only once he did something of which I thought: he shouldn’t have done this, it’s wrong.
In 14d ‘Setter’s’ is surely not I’M – ‘Setter’s’ here not being equal to ‘Setter is’.
And Pete, you say (in 11d – DASH OFF) “Cinephile’s is very good at clues of this type!”, the exclamation mark suggesting that you really like it. Well I don’t. Indeed, in solutions consisting of two words, Cinephile often clues them separately, but that’s exactly what I don’t like.
I am not completely convinced by 17d (VIENTIANE).
IN E with NATIVE dress, is for me INE surrounded by an anagram of NATIVE – which here it’s not.
In 15etc ac KEEP is indeed ‘look back’, but seen as PEEK backwards.
My favourite clues: the ACTIVITY of 27ac and the Libertarian construction of 24d (LATIN).
And a very fine misleading surface in 1d (HATRACK).
BTW, I have no problem with the use of ‘Manx’, seen this many times before.
Re (my own) #2:
On second thoughts I withdraw my remarks on IMPETUS (and the use of I’M).
Of course, it can be read as ‘Setter is favourite American’. Sorry.
[I am always very suspicious when this setter uses ‘apostrophe s’ – sometimes he can be wrong(ish) in its use, sometimes he’s right (like here)]
I didn’t like 27ac: it’s ‘One caught by creeper keeping it in business’ really, and could perfectly well have been clued thus. The surface and intent of the published clue (‘One caught by creeper keeps it in business’) seem ungrammatical: ‘a ct’ is next to (= by) something. To what? To ‘creeper keeps it …’? Surely no.
Wil (#4), you’re absolutely right.
Don’t know why I’ve written down 27ac as one of my favourites.
Well, I do know. I confused it with a solution in his O(pera) puzzle (FT 13,306) which I solved at the same day.
Still, do like LATIN and HATRACK.