CAPTAIN AMERICA replies.

Friend, I grew up on a Brooklyn block where my ma knew every name on the street and half the names on the streets beyond it. The Depression was still fresh in people's bones when I was small. And somehow there were still plates of food at somebody's door when they got sick, still a neighbor watching the kids when somebody else had to pull a double. Nobody kept books on any of it. The books would have embarrassed everybody.

Those neighbors of yours weren't running a transaction. Mrs. Kowalski didn't hand over her sugar ration because she's collecting on it later — she gave it because she wanted to be the kind of person who does. Every one of them did. The reason they won't accept anything in return isn't false modesty. It's because taking payment would turn what they did into a job, and it wasn't a job. Your trying to settle the account is actually the one thing that would make it strange.

So here is the thing you do instead. Learn her name if you don't already know it beyond the nod at the grocer's — her whole name. Put the block warden's number somewhere you'll find it at two in the morning. Then stay ready. Because somewhere on that street, inside the next year, somebody else is going to be standing in six inches of water. And now you know exactly what showing up looks like — you've seen it done right in front of you. That is the only currency they were ever spending, and it's the only kind they'll accept back.