Is there a difference between the following:
(A) In 18th century, he worked on a novel, which would later be cast into a film.
(B) In 18th century, he worked on a novel, which was later cast into a film.
Add 'the' before '18th', omit either one of the commas, change 'cast' into 'made' and there's no difference.
A better title would have been 'Which would later be cast/which was later cast'.
Extract from the Posting Guidelines:
'Thread titles should include all or part of the word/phrase being discussed.'