Bitter detectives entering area beginning to uncover corrupt soul (9)

I believe the answer is:

acidulous

I'm a little stuck... Click here to teach me more about this clue!

'bitter detectives' is the definition.
'acidulous' can be an answer for 'bitter' (I've seen this before). I'm unsure of the 'detectives' bit.

'entering area beginning to uncover corrupt soul' is the wordplay.
'entering area' becomes 'acid' (I can't justify this - if you can you should believe this answer much more).
'beginning to' says to take the initial letters.
'corrupt' is an anagram indicator.
The first letter of 'uncover' is 'u'.
'soul' with letters rearranged gives 'lous'.
'acid'+'u'+'lous'='ACIDULOUS'

Can you help me to learn more?

(Other definitions for acidulous that I've seen before include "Sharp" , "Bitter" .)

I've seen this clue in The Independent.

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