Not now, in that case (4)

I believe the answer is:

then

I believe this clue is a double definition.

'not now' is the first definition.
(I've seen this in another clue)

'in that case' is the second definition.
(synonyms)

(Other definitions for then that I've seen before include "Afterwards - as a result" , "At that time; next" , "Subsequently - previously" , "Consequently" , "soon?" .)

I've seen this clue in the Evening Standard.

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