Possible Clues:

• End to a bully's threat
• Ominous final words
• "Otherwise, I might do something you'll regret!"
• End of a blackmail threat
• 'Otherwise ...'
• '... if not, you'll live to regret it!'
• 'Speak fair words, — — be mute' (Shakespeare, Venus and Adonis)
• Bully's last words, maybe
• Words that warn you
• ". . . unless you want trouble"