Scheme to finish up with a fortune (4)
I believe the answer is:
plot
'scheme' is the definition.
(plot is a kind of scheme)
'finish up with a fortune' is the wordplay.
'finish' indicates one should take the final letters.
'with' means one lot of letters go next to another.
'a fortune' becomes 'lot' ('lot' can be a synonym of 'fortune').
The final letter of 'up' is 'p'.
'p'+'lot'='PLOT'
'to' acts as a link.
(Other definitions for plot that I've seen before include "Scheme or small piece of land" , "Gunpowder, for one" , "Scheme; graph" , "bed" , "are intriguing" .)