Possible Clues:

• Fen route (anag)
• One might often rue this in a number of ways
• Lines in a sonnet
• Often rue wobbly figure
• No. of lines in a sonnet
• Ernie Banks's retired uniform number
• With 56 Across, year of Columbus' voyage
• The number to get in line for 1 across
• A number take the wrong route into the bog
• Score six below