You open the mailbox, and there it is: a notice from the IRS. They say you owe them several thousand dollars of back taxes, which you don't have, from a couple of years ago. The revenuers are coming at you with some highly technical and complicated legal arguments. They say you owe penalties. And every day, the interest on your newly discovered debt is piling up -- as it has been for a couple of years since you filed the tax return in question.

Maybe the bill is because of something your ex-spouse did or didn't do back when you were together. Like just about all married couples, you filed a joint tax return because it was cheaper. But the fine print says that you're both liable for each other's taxes now. Your ex disappeared from the scene last year, and this isn't the only leftover bill from that marriage that you can't pay.

Where can you turn for help? A tax lawyer or accountant? You call around. They'd charge as much as the tax, if not more, and there's no guarantee they can do anything for you. They want a retainer up front -- a retainer you don't have. Is there anywhere else you can go?

If it were 10 years ago, the answer would be no. But beginning about a decade ago, a very small and very bright band of energetic tax professionals convinced Congress that the answer ought to be yes. And now, in most major cities, there are low-income taxpayer clinics that help taxpayers in situations like the one I've just described. Sometimes the taxpayers owe what the IRS says they owe, but in a surprising number of cases, it turns out that they don't. And it takes the clinics, mostly staffed by unpaid volunteers, to vindicate the rights of the ones who don't.

The federal government pays for half of the clinics' operations, and private outfits (many of them law schools) chip in the other half. Here in Portland, we've had a clinic like this for the last six years or so.

I bring this up because one of the bright band has died. Janet Spragens, a professor at American University Law School in Washington, D.C., was a tireless advocate for the rights of low-income people caught up unfairly in the tax system. Everyone connected with the clinic programs looked up to her, and she proved how much good one dedicated and civic-minded person can still do in this country.

At the tax lawyers' convention I attended a couple of weeks ago, they gave an award to Janet, in appreciation for the countless hours of volunteer work she did for the good of others. She was too ill to be there to accept it, but she was a brilliant and perceptive person, and I'm sure she understood just how greatly she was appreciated.

I met her only once, at an early conference at her school on the clinic grants, but I feel as if I knew her. It's going to take some time to get used to referring to Janet in the past tense. She was in her early 60s.