Think you know your literature? Can you name the captain of the Nautilus?

As a detective in this case, I would first analyze the clue and break it down into its key components. ‘Fictional captain‘ suggests that the answer would be a character from a work of fiction who holds the rank of captain. ‘Nautilus‘ provides a more specific hint, as it is a well-known vessel from Jules Verne’s novel ‘Twenty Thousand Leagues Under the Sea.’

Based on this information, I would begin to think of potential characters who fit the description of a fictional captain who commands the Nautilus. After some consideration, the name ‘Captain Nemo‘ would come to mind as a possible solution. As the main character in Verne’s novel, Nemo is a mysterious and enigmatic figure who commands the Nautilus, possessing a complex personality that combines both heroism and villainy.

To confirm this deduction, I would cross-check the answer with the other clues in the crossword puzzle to ensure it fits all the necessary criteria. After determining that ‘Nemo’ satisfies all the requirements, I would confidently fill in the answer and solve the mystery of the fictional captain of the Nautilus.