Wonderful, not that then? (9,4)
I believe the answer is:
something else
'wonderful not' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'then?' is the wordplay.
I cannot quite understand how this works, but
'then?' could be 'so' (both can mean 'therefore' or 'in that case') and 'so' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'that' is the link.
Can you help me to learn more?
(Other definitions for something else that I've seen before include "exception" , "A different (and special) item" , "Another item?" .)