Subsequently coming up in adventure tale ... (5)
I believe the answer is:
later
'subsequently' is the definition.
(I've seen this before)
'coming up in adventure tale' is the wordplay.
'coming up' says the letters should be written in reverse.
'in' says the answer is hidden in the clue.
'retal' can be found hidden inside 'adventure tale'.
'retal' back-to-front is 'LATER'.
(Other definitions for later that I've seen before include "After a given point in time" , "Subsequently" , "at a subsequent point" , "In due course" , "there's more behind" .)