Resolved questions
what is the “a-ha gesture” in the sentence？

She shrugged. “It’s one of those days where it’s a little hard to be Sutton Mercer. I would give anything to get out of here. Get a break from being Sutton for a while.”
A wrinkle formed on Ethan’s brow, and then he held up one finger in an a-ha gesture. “Absolutely. And I know exactly where I can take you.”