Make no mistake about it -- Farley Mowat is angry. He is furious. If prose could be made to sputter in rage, this tiny book would sputter. It is a righteous anger, the kind that bristles with those powerful satisfactions that come when you have been done dirt and can prove it and now have the opportunity to tell the world about it in exquisite detail. Most of us can only yell at the wife or kick the cat. Mowat gets a book.

You can't blame him, really. On April 23, 1985, the Canadian author went to Toronto's Lester B. Pearson International Airport to begin a U.S. promotional tour for his book "Sea of Slaughter," an account (angry) of the depredations mankind has inflicted through history on the wildlife of the North Atlantic coast. After going through a routine customs check, Mowat's boarding pass was stamped and he took a seat to wait for departure. Then an officer of the U.S. Immigration and Naturalization Service (INS) appeared at his side and asked him to "follow me, please" -- perhaps the three ugliest words in the English language when they are uttered anywhere near an international border.

Mowat followed, only to be told, " 'You are excluded from entering the United States.'

"He issued this stunning dictum with a righteousness that would have suited St. Peter turning a poor sinner away from the Pearly Gates.

" 'I what?'

" 'You are not permitted to enter the United States of America.' He was being patient now but, I suspect, enjoying himself.

"I, most assuredly, was neither.

" 'Why in blazes can't I?'

" 'I can't tell you that.'

" 'You know, but you bloody well won't tell me?'

" 'You could say that.'

" 'I could say that! Who will tell me? What in Christ's sweet name is going on here?' "

What was going on here was the United States of America making a great ass of itself. The INS agent had run a quick check on Mowat and the computer had spat his name out as an undesirable. His name was on a list. There was a folder on him. He was in the INS "Lookout Book" as an official Nasty Person not admissible to the United States. The enabling legislation here was the McCarran-Walter Act, that relic of the early Cold War that stipulated any number of reasons, including the theory and practice of anarchy, why a person might be considered dangerous to "the welfare, safety or security of the United States."

Mowat, it seemed, had been a member of the Fair Play for Cuba Committee in the 1960s. He had supported the campaign for nuclear disarmament. He had written a book about Siberia. He had once, in 1958, put his name to a slightly drunken manifesto regarding SAC bombers based in Newfoundland that the press managed to interpret as threatening. Any or all of these were apparently enough to strike consternation in the heart of Benedict Ferro, the INS district director who had ordered Mowat's exclusion.

Mowat and his publisher wasted no time getting the word out to the Canadian multimedia. Not since the Fenian Invasion of 1866 had there been such outrage against the United States. The U.S. press was only a little less frenzied. The response of our government to this superflap was a gummy mix of stupidity and bureaucratic waffling that finally ended up in a sort of apology that Mowat sort of rejected. And there it might have rested.

But no, there had to be a book -- or a bookette. "My Discovery of America" is a little longer than a typical John Updike review of an obscure Bulgarian novel in The New Yorker and a lot shorter than a Travis McGee adventure. It is, in truth, little more than a badly written magazine article padded out to pass for a badly written book. The padding is in the form of newspaper stories and editorials and radio and television interviews -- lots and lots of them, so many that the reader's own sympathetic outrage over this insane twitch of frantic anticommunism is soon leached away by an overwhelming boredom. Mowat, who has written some good and necessary books ("Never Cry Wolf" and "A Whale for the Killing" among them), should have strangled the impulse that led to this one, even if it did make him feel better.