well - fibonacci is not wrong by saying ' openended' on the information that you gave him .... but, I do not think that 'openended' is the right answer for thye clue given.
The clue is either -
Closing Statement, perhaps (cryptic clue)
Epilogue (quick clue)
Is the answer not 'Afterword'?
17d is dragged - the letter 'a' of which is the starting letter for 25a