Possible Clues:

• Ripley's closing words
• Second-guessing phrase
• "... never mind, then"
• ''Believe it __ . . .''
• '... but maybe I'm wrong'
• '... but possibly untrue'
• 'Believe it !'
• "Ripley's Believe It ___"
• Herbie Hancock "Ready ___"
• Jackson Browne "Ready ___"