Across:
1 It’s fine, for example (fine = PUNISH), to sell drugs (PU-SH) around Ulster (Ulster = Northern Ireland = -NI-) (PUNISH),
4 Take a draw (SMOKE) when not at home (OUT) (SMOKE OUT) – with this approach there’s no hiding place (SMOKE OUT),
9 Channel Islands (CI-) connections (-TIES) (CITIES) to London and Paris (CITIES),
10 Last (= position indicator) drugs (E+E = -EE) deal with (ATTEND- to) (ATTENDEE) partygoer (ATTENDEE),
12 Half of the characters in 1 down (half of ‘picklock’ = LOCK-) contact forger (forger/ -SMITH from forge) (LOCKSMITH) as he knows his way around Yale? (LOCKSMITH / Yale key),
13 Disrespectful dismissing culprit’s (‘disrespectful’ dismissing ‘culprits’ = dseef = FEEDS) supplies (FEEDS),
14 Pay attention to (CONCENTRATE-) The Last Word (the last ‘worD’ = -D) (CONCENTRATED) – it’s the epitome of deep thought (CONCENTRATED),
18 Confusion (ASTONISHMENT) in a (A-) street (-S-T) over Shinto (Shinto) shift (= anagram indicator) (Shinto = -TONISH-) workers (-MEN-) (ASTONISHMENT),
21 Odd (= anagram indicator) thing (thing = NIGHT) is – this is one for the stars (NIGHT),
22 It’s a feature of the Mediterranean (AEGEAN SEA) that this divides the Greeks and the Turks (AEGEAN SEA),
24 Mascot in (mascot in) play (= anagram indicator) (mascot in = MONASTIC) describes being confined to a cell all day (MONASTIC),
25 Boss (= anagram indicator) fined (fined = F-IEND) over writing (from the 3Rs = -R-) (FRIEND) to intimate acquaintance (FRIEND),
26 One of those with bug (LISTENER) let siren (let siren = LISTENER) off (= anagram indicator),
27 Made an impression on (MARKED) writer (marker) briefly (r) (‘marker’ without ‘r’ = MARKE-) with director (-D) (MARKED).
Down:
1 Decide on (PICK-) bar (LOCK) (PICKLOCK) to steal from (PICKLOCK),
2 Without failing to grasp it (NOTICING), Dan is out of gin and tonic (‘Dan’ is out of ‘gin and tonic’ = gintonic = NOTICING),
3 Moves (STEPS) by spymaster releasing army (‘spymaster’ releasing ‘army’ = spste = STEPS),
5 Session in court (tennis MATCH-) fabricating (-MAKING-) extreme falsehoods (extreme ‘falsehoodS’ = -S) (MATCHMAKINGS) setting up numerous potential partners (MATCHMAKINGS),
6 Chill (KEEP FRESH) in brand new (FRESH) castle (KEEP) from the start (= positional indicator) (KEEP FRESH),
7 Presumably, the first males in The Bible (OLD MEN) with greybeards? (OLD MEN),
8 Devout type (THEIST) of teller from the start (‘Teller’ from the start = T-) gets bank job (-HEIST) (THEIST),
11 Make up stories (FICTIONALISE) and lies (FICTION-) on the greatest (‘the greatest’ Muhammad -ALI-) lead singer (lead ‘Singer’ = -S-) with One Direction (East = -E) (FICTIONALISE),
15 Wild (= anagram indicator) yeast (yeast = EASY T-) and a fair amount of (half of) the pasta flour (half of ‘OO’ flour = -O) on view (SEE) (EASY TO SEE) is staring one in the face (EASY TO SEE),
16 Novel (NEW-) by Old Bob (‘old bob’ = shilling = -S-) and Ben in Scotland (ben = -PEAK) (NEWSPEAK) is written with a nod to Orwell (NEWSPEAK),
17 Description of Robinson Crusoe (STRANDED) by a Bandon (abandon = STRAND-) journalist (-ED) (STRANDED),
19 Line managers dishing out greens (‘line managers’ dishing out ‘greens’ = limana = ANIMAL) with chicken (ANIMAL)
20 Ream from East German (‘ream’ from ‘East German’ = eastgn = AGENTS) spies (AGENTS),
23 Loses the head (p) on drink (‘port’ without ‘p’ = -ORT-) and goes into Alcoholics Anonymous (A-A) (AORTA) – will the cardiologist be able to handle it? (AORTA).