Possible Clues:

• Aha!
• Make rueful, somewhat reflective, exclamation in bath?
• I've found it! (Archimedes)
• Triumphant cry of Greek getting European perks, as regularly given
• Suddenly get it from revelation
• Evidence of a discovery by Poe?
• Triumphant cry
• Set up for take mostly on nice street for A Cry of Joy
• Cry on a great discovery
• "I have discovered it!"