Vast epic about those taken prisoner (8)

I believe the answer is:

captives

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'prisoner' is the definition.
(I know this)

'vast epic about' is the wordplay.
'about' is an anagram indicator.
'vast'+'epic'='vastepic'
'vastepic' is an anagram of 'CAPTIVES'.

'those taken' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.

Can you help me to learn more?

(Other definitions for captives that I've seen before include "Prisoners, hostages" , "They are held as prisoners" .)

I've seen this clue in the Sydney Morning Herald.

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