Related Clues:

• How often opportunity knocks
• This person's got caught entering previously
• Sole yet to be filleted has head removed, fifty caught
• Individual catching cold in the past
• A single time in concerto
• "I remember the time ..."
• By a single step
• ... upon a time for the storyteller
• Single in Lyon, sadly
• At one time part of population census
• Eleven, in Ensenada
• Violence without evil ... that's the start of an old story
• At some early date
• Spin Doctors "___ in a while someone lives happily ever after"
• On the off chance both sides do it without repeating it