Across
Poetic work the first with dramatic stakes? Guess not... (13)
I haven't cracked this one yet — but Fifteensquared have:
D[ramatic] + antes(=stakes, in betting) + infer no(=guess not)
Detective to probe corrupt Vatican ruler's principles (15)
I haven't cracked this one yet — but Fifteensquared have:
DI(=Detective Inspector) in (Vatican ruler’s)*
What holy folk will give in Frankie and Benny's maybe? (15)
I haven't cracked this one yet — but Fifteensquared have:
CD
Latin poet's moving verse for abyss (4)
I haven't cracked this one yet — but Fifteensquared have:
Ovid, a poet responsible for The Metamorphoses, with the v{erse} moving to the front
Location down under home to certain devils reclining on throne? (3)
I haven't cracked this one yet — but Fifteensquared have:
I must confess to having to look at the puzzle annotation to explain this one but it’s Tas{mania}< with reclining providing the reversal indicator. The devils refers to Tasmanian Devils, which are a type of marsupial indigenous to Tasmania.
Mephistopheles initially leading wicked staff (4)
Accused person may enter this place with endless heat (4)
I haven't cracked this one yet — but Fifteensquared have:
Pl{ace} + [h]ea[t]
Casino's hosting 21 perhaps (3)
Fire and brimstone beginning to affect label on pants (4)
I haven't cracked this one yet — but Fifteensquared have:
S{ulphur}(=brimstone) + a[ffect] + CK(=Calvin Klein, label of a US fashion brand). The def is in the sense of dismissing someone from a job.
Fiendish act I'm in on with liar is creating offence (15)
Obviously diabolical spirit's vile and tart when drunk by yard (15)
I haven't cracked this one yet — but Fifteensquared have:
Demon’s(=diabolical spirit’s) + (vile tart)* + y{ard}
Underground Zones 1-9 – might four answers here be called one of them? (13)
I haven't cracked this one yet — but Fifteensquared have:
The 9 circles of hell features in Dante’s Inferno and might be described as in the clue. The second part refers to the isolated middle section of the puzzle where the four words form a circle containing the word “satanist”.
Down
One taken in by proof all made up (9)
Caught on top of tower with specially picked locks (7)
I haven't cracked this one yet — but Fifteensquared have:
T[ower] + wigged(=specially picked locks i.e. hair)
Second husband a big hit – or old hat (5)
I haven't cracked this one yet — but Fifteensquared have:
S{econd} h{usband} + a KO(=knockout, which could mean a big hit either in a boxing sense or in the colloquial sense of something that’s very successful)
Church centres called out scoundrels (5)
I haven't cracked this one yet — but Fifteensquared have:
Hom of knaves(=scoundrels)
Body part some heard rumbling (7)
Futile gesture snubbed by crossword setters online (5)
I haven't cracked this one yet — but Fifteensquared have:
No[d](=gesture with last letter “snubbed”) + us(=crossword setters) + E(=online, as in E-commerce)
Reminder to include right solution (4)
A couple of significant others nothing to write home about (4)
I haven't cracked this one yet — but Fifteensquared have:
S{ignificant} o{ther} twice
NASA program regularly blocked sites (3)
I haven't cracked this one yet — but Fifteensquared have:
Odd letters of s i t e s. I’d never heard of it but apparently STS (Space Transportation System) is the official name of the Space Shuttle Program.
Successfully sunbathe in vessel with bottom out (3)
I haven't cracked this one yet — but Fifteensquared have:
Tan[k]
Firm friend swallows pill before large red (9)
I haven't cracked this one yet — but Fifteensquared have:
(Co{mpany}(=firm) + china(=friend e.g. “my old china”) + l{arge}) around E{cstasy}(=drug usually sold as pills). Cochineal is a red colouring made from insects.
Insiders from navy like a certain Bond dealing with gadgets in the air (7)
I haven't cracked this one yet — but Fifteensquared have:
[N]av[y](inside letters) + ionic(=type of bond in chemistry)
Rejecting siestas I don't say a word in this language (7)
I haven't cracked this one yet — but Fifteensquared have:
Naps<(=siestas) + I + sh(=don’t say a word)
The first day of advent's flipping cold (4)
I haven't cracked this one yet — but Fifteensquared have:
(Dec I)<(=first day of Advent)
What sounds just like its heart's desire (4)
Newspaper carrying Methuselah's second-rate bits of verse (5)
I haven't cracked this one yet — but Fifteensquared have:
I(=the I newspaper) with “I am B” (B=second-rate as in B-list celebs) on top of it
One who's six feet under concerned with cave (5)
I haven't cracked this one yet — but Fifteensquared have:
Ant(=one who has six feet under) + re(=concerned with)
Amigo spoiled how The Metamorphosis ends (5)
Type letters or click words in the clue