I'm sometimes asked if I ever do spy/espionage-type stuff. And the answer is—yes!
I once went out to a client's house at 1:00AM. I parked, got out of my car, and knocked on a side door. Despite the late hour, he answered.
Silently, he let me in.
"Where's the info?"
"On my right foot."
He chuckled. "An interesting place to put it."
"It was the most secret spot I could think of writing it on, easily."
He led me to the kitchen. I sat in a chair, took my right shoe off, and crossed my foot.
There were two bottles and paper towels on the table. He opened one bottle, poured some of the liquid on a towel, and gave it to me. I rubbed it on my foot, by the arch and the heel.
A message appeared.
He walked over to read it. Then he took out an electronic note pad and typed the message on it.
He then poured some of the second bottle's liquid onto another towel and gave this to me. I rubbed it on my foot, and the message washed away.
"Can I have some water, please?"
He took a towel and wet it down in the sink. Then he gave it to me. I cleaned my foot off with it. Then I took one of the dry towels and dried my foot. Finally, I put my shoe back on.
He took an envelope out of his pants pocket and gave it to me. Inside were five $100 bills.
I nodded. "Thanks. I'll contact you when I get more info."
We got up. He followed me to the door.
"You've got a very nice foot!," he joked.
I smiled. "Perhaps I'll show you my other one, next time!"
Why so secretive? I was investigating a potential spy in his company, and that's how he wanted to best get the info I was gathering.