Related Clues:

• Opportunity's frequency
• Fairy-tale beginning
• How coffee filters are used
• First word of 'The Raven'
• 'There was a time ...'
• "___ bitten, twice shy"
• In olden days
• In days of yore
• Second word in many a limerick
• Without repetition
• Never again
• Back in time
• "Going ___, going ..."
• At the moment when
• Start of a tale