Will delve about in, you conclude (6)
I believe the answer is:
finish
'conclude' is the definition.
(I've seen this before)
'will delve about in' is the wordplay.
I cannot quite understand how this works, but
'in' is within the answer.
The remaining letters 'fish' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'you' acts as a link.
Can you help me to learn more?
(Other definitions for finish that I've seen before include "Bring to an close" , "surface texture" , "Conclude, end" , "perfection" , "Put the final touches to" .)