Related Clues:

• Number suggested by 53-Across
• 'Terrible' age
• Thematic number on 61-Down
• Late lunch hour
• 'Tea for --'
• Word in a sequel title, often
• Tango minimum
• The only even prime number
• A quarter of eight?
• I and I
• Duet necessity
• Tandem bike's capacity
• Four halves
• Helium's atomic number
• 40 Across and 40 Across