Daniel slipped his phone into his pocket and pulled the computer onto his lap. “What am I looking at?”

“I don’t know. That’s the problem.”

“You don’t know what this is, but you think it’s worth stealing?”

Daniel was starting to remind me of Dr. Stetler. I wanted to smack his smug face. “Obviously, someone knows what it is.”

“Yeah,” Daniel said, “and that someone is dead.”

“And maybe that someone is dead because of what’s in this file.”

Daniel looked up from the screen and stared at me. “Are you serious?”

It was the first time I’d said it out loud, but the thought had been percolating in my head all day. “I don’t know. Maybe.”

“Then you must have some guess as to what you think this is.”

I hesitated, wondering how much I should share with Daniel. But I’d gone this far. I might as well go all the way. “At first I thought it was a list of account numbers. But every bank account number I’ve ever had is just a list of numbers, not letters too, and never this long. Now I’m thinking maybe they’re passwords.”

“Passwords to what?”

“I have no idea.”

Daniel scrolled down to the bottom of the spreadsheet and back up to the top again. “You know what these look like to me?”

“No, what?”

“Private keys.”

Chapter 23

“What’s a private key?” I asked.

Daniel drained his wineglass and moved it off to the side, then placed the open laptop in the center of coffee table. “You know what cryptocurrency is, right?”

“You mean Bitcoin?” I didn’t own any and didn’t really understand how it worked, but I knew lots of people thought it was valuable and some of those people had made a ton of money investing in it.

“Bitcoin is one form of cryptocurrency, but there are lots of others. Do you know how digital currencies work?”

“No clue.”

Daniel started by explaining blockchains and smart contracts, and by the time he got to the cryptographic algorithm hash, I was hopelessly confused. “Can you please just tell me what a private key is?”

“Essentially, it’s a password. When you purchase cryptocurrency, you get two keys—a public key and a private key. Both are alphanumeric strings like these,” he said, gesturing to the spreadsheet. “Think of the public key like an email address or a phone number. You can give it out to anyone. But the private key works like a password, so you need to safeguard it. To access a digital wallet, you need both the public key and the private key.”

“So it’s like a safe deposit box at the bank? You need both keys to open it?”

“No, because the public key is information anyone can get. Only the bank has access to the bank’s safe deposit key. But you do need both keys to open a digital wallet, so in that sense, they’re the same.”

“You’re saying if someone knows my public key and then they find my private key, they can open my digital wallet and steal all my money?”

“Yes. But unlike money held in a bank, there’s no central clearinghouse for cryptocurrencies. If someone steals your digital currency, you have no recourse; there’s no one to call to get your money back.”

“What happens if I lose my key?” I’d forgotten my passwords plenty of times.

“This is one password you definitely don’t want to lose. You can’t access your digital wallet without the private key. And it’s not just cryptocurrencies that work this way. It’s NFTs too. You know what those are, right?”

“Um, sort of.” I’d heard the phrase before, of course, but I didn’t actually know what the letters stood for.

Daniel pulled my computer into his lap and started typing. Then he turned the screen to face me. I was staring at a gallery of digital artwork. “All of these are NFTs,” he said. “Non-fungible tokens.”

“Digital prints?” I asked.

“Not prints. They’re digital only.”

“So I can’t buy one of these and have it shipped to me?”

“When you buy an NFT, all you’re buying is a digital token on a blockchain.”

“And what can I do with that?”

“Hold onto it, trade it, hope it goes up in value.”

“Like a baseball card, but digital only, no physical card?”

“No, the artist who created these might have physical copies, but you’re only buying a digital one.”

“What’s to stop the artist from making and selling more digital copies?”

“Nothing.”

This was making my head hurt. “I don’t understand. If the artist can make more NFTs whenever they want, then why does my NFT have value?”

“Why does any art have value? Because people think it does.” Daniel reached for the laptop again and pulled up a video of two toddlers fighting, which I vaguely remembered watching when the clip had gone viral a couple of years ago.

“That one sold for over half a million dollars.”

“No way! I watched it for free.”

“You can still watch it for free.”

“Then why would someone pay half a million dollars for it?”

“Because now they own it.”

This felt like a giant Ponzi scheme. “I think I’m in the wrong business. I should be making viral videos and selling them as NFTs.”

Daniel laughed. “A lot of people feel that way right now.”