Jules Verne's submarine captain (4)
I believe the answer is:
nemo
'jules verne's submarine captain' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for nemo that I've seen before include "Fish sought in film" , "Finding -, animated film" , "Literary captain" , "Captain brought to book" , "commander for the Nautilus" .)