Possible Clues:

• Line of cotton - plot (of book, film)
• It gets poked in the eye
• Twine
• Group of online posts
• What some following story can lose — in the unfinished book, say
• It's for a nut to have one in stitches
• May be cut in a way that'll have you in stitches
• Strand of yarn
• Study after the unfinished yarn
• Strand, cord