Related Clues:

• Sudden understanding
• Cry upon figuring out 66-Across
• "I'm onto your scheme!"
• It's "eureka!" either way
• 'Here's the answer at last!'
• Bingo alternative?
• "I finally get it!"
• "Well, what have we here?"
• Exclamation of knowledge
• 'Now it makes sense!'
• Cry made with a raised index finger
• ''Of course!''
• 'Found you!'
• 'Caught you red-handed!'
• 'And what have we here!?!'