Possible Clues:

• '... because you don't want to cross me'
• Unspoken alternative
• Blackmailer's conclusion
• '... and if you don't, there will be consequences!'
• Words in a threat
• 'Should that not be the case . . .'
• Often-unstated ''otherwise''
• Threat-ending phrase
• Part of a vague ultimatum
• "... you'll be sorry if you don't!"