In Terry Galanoy's view, the tyrant that has been stealthily undermining the economy, threatening our privacy, our freedom and our institutions, driving innocent families, widows and orphans into debt and despair is not world communism, OPEC or the cockroach, but a shiny 2-by-3 1/2-inch piece of plastic called a bank credit card. Bank credit card? That's Visa and MasterCard, to name the two leading giants in the field.

How they go about their deadly work, what they have already done to fuel inflation and what their implications are for the future are the themes of this book. They are themes we should all be thinking more about; themes that most of us only dimly understand.

Unfortunately, although there is enough alarming material in these pages to stand your hair on end for a week, or make you spindle your bank cards and kick the next banker you meet in the shins, it is so chaotically organized and delivered in such a loopy and haphazard way that only the best and the bravest will slash their way to the end, where, in fact, some of the author's most gripping revelations lie in wait.

He pays tribute among the "credits" to his agent, his editor at Putnam, his researcher, his editorial assistant and someone named Bill Flaxman, "who helped get this project off the ground by getting me back to earth." What he needed more than all of these was the rumple-faced man in sleeve garters a lot of us had to face in our youth, who wrote "How, pls?" and "Sex who?" in the margins until our copy got so lean and mean and tightly built that to shift one sentence would bring the whole contraption to the ground.

"If you're average," Galony blithely states, "you have some eight credit cards in your wallet, and two or three of them are bank cards." Maybe all those people don't need any explanation of the basics. But some of us out here seem to have missed out on those cards, and if we're going to get sore about them, we've got to know what they are. How do you get them? How do they work? Who pays what to whom? What sets them apart from the plastic you get from Lord & Taylor and American Express?

Galanoy keeps promising to spell out the basics, but he is so anxious to tell us what's wrong with the cards now, and what's going to be even more wrong with them in the future, that he keeps getting ahead of himself. By the bottom of the first page he's already depicting the horrors of Lifebank, an Orwellian word he has coined to describe the ultimate credit card system of a cashless society in which our entire lives will hinge on electronic transfers of money and goods. One false punch on the keyboard could wipe us out, the most intimate details of our life are laid bare in a central data bank, available to all who can push the right buttons or pull the right strings, and if we lose our credit standing we could virtually cease to exist.

It is a galvanizing and all-too-possible perspective, but how do we get there from here? Galanoy seems more intent on being folksy (the credit bureaus will "find you faster than dandruff finds blue serge") than in making sure the whole class can follow where he leads.

Ultimately, the picture that so fitfully emerges is enough to make you turn in your bank cards for life. Banks send them to people, whether they have an account with the bank or not. At first, banks sent them unsolicited through the mail to the names on rented lists, including at least one dog. Along the way they were stolen and strayed into the wrong hands and people brought out stores and left town before they could be caught. Stores that honor the cards pay what the banks call a fee and Galanoy calls a "kickback" to be a member of the system. The bank pays the store for what you bought and sends you a bill (or takes the money directly out of your checking account, if it's a "debit" card from your own bank).

If you're late paying up, you start to owe the bank 18 percent a year, or more, depending on the bank and how it figures its bills. If you buy what you can afford and pay right away, the cards can be a convenience and you're home free. But so many people are using them to buy what they can't pay for that in some areas, Galanoy writes, one out of every 25 families files for bankruptcy.

In the big picture, the cards "pollute the inflation rate," by prodding people to spend money they don't have. They are a sort of wild money supply, unsupported by any real value, set loose in the economy by the banks and beyond the control of the Federal Reserve, which is officially supposed to be controlling the money supply to keep us from the brink of ruin.

In addition, as Galoney keeps insisting from the start, they are a first giant step along the road to the faceless computers that can seize control of our lives. His guided tour of the never-never land of computer fraud is one of the most illuminating and arresting parts of the book. If the journey to this lucid oasis had been less arduous, you'd be in better shape to enjoy it.