Who knows what evil lurks in the hearts of men?

The Shadow knows.

The Shadow lives.

The cloaked crime fighter, remembered for his blazing automatic and the eerie laugh that chilled his victims and radio listeners from 1936 to 1952, is somewhere in the city. He's in disguise, of course, but not that of Lamont Cranston, man-about-town.

He is 80 years old, white-haired, heavy-set. He answers to the name Walter Gibson. Or Maxwell Grant.

Maxwell Grant was the pen name used by Gibson when he wrote all 282 Shadow novels (averaging more than a million words a year for 15 years that used to sell up to 300,000 pulp copies each almost as fast as they hit the newsstands. The books, some of which were recently reissued in paperback, became the basis for the famous radio series and eventually made the author a cult figure.

The Shadow did not die in 1952: Today, as part of the interest in nostalgia, there are Shadow clubs, Shadow collectors, and correspondents who write Gibson letters addressed simply, "The Shadow, 12426," his ZIP.

"It got to be part of my life," he says, in obvious understatement. "The closer you got to it, the faster the ideas came. I was getting ideas all the time. I got five or six months ahead and stayed that way."

"The Living Shadow," "The Eyes of the Shadow," "The Shadow Laughs," "The Black Master" . . . all were titles that launched The Shadow on the trail of evildoers everywhere - a "character of unlimited scope" that Gibson says he created "by combining Houdini's penchant for escapes with the hypnotic power of Tibetan mystics."

A magician himself and author of 125 other books, many on magic, Gibson used to travel with Thurston, Houdini, Blackstone and Dante, and is linked to yet another celebrated illusionist, the late Great Raymond. He is married to Raymond's widow. Gibson has chosen this weekend to appear in Washington to take part in today's ninth annual gathering of the International Brotherhood of Magicians, Washington chapter, at the National Press Club.

Foiled by Washington traffic, which never would have slowed The Shadow, Gibson arrived at the press Club on Thursday a bit late and out of breath. He sank into a chair, adjusted his glasses, and, magically catching his wind, began telling stories.

He tells them as fast as he used to write them - and he could write a 60,000-word Shadow novel in four days. A deadline wizard on Philadelphia papers in the early 1900s.Gibson gained a considerable reputation for speed, so that when he walked in to the Smith & Street publishing office in New York one day in 1931 to peddle some detective stories, the editor said, 'You're just the man we want to see. We want four novels - fast.'

Another Street & Smith official had the idea for The Shadow; their only instruction to Gibson was to hit his typewriter keys and get back to them in a hurry. Oh, yes, he was told, introduce a Chinatown angle in the first novel because, to save money, they planned to use a handy cover that happened to have a Chinese figure on it. Gibson obliged with an early chapter titled "The Tea Shop of Wang Foo."

"Once I got the tempo of the pulps," he says, "I would suddenly get a new idea, like getting up a new trick.If an idea came up in the course of a story, I'd lay it aside for another story. I had a backlog of incidents. For example, I was doing research into castles in England and came across a description of the Golden Arrow train. I began to think of some murders taking place on this train." And so came the opening pages of "Zemba . . . legendary Parisian arch-criminal."

"The whole thing built itself up," Gibson says. "I'd write whenever I wanted as long as I wanted. Usually, once I got writing I didn't quit. I was always writing faster at the finish."

He even had time left over. 'I knocked out an occasional book. I edited a magic mazine . . ."

The "master fighter whom all gangdom feared" became so popular so fast that in 1932 - "That's when I hung up the record," he says - he was asked to deliver one million four hundred forty thousand words, or 24 stories at 60,000 words each. He did it in 10 months and then wrote four extra novels for a total of 1,680,000 words. (He figures he's written 29 million words lifetime, including such numbers as "Thurston's 200 Tricks You Can Do," "Bunco Games to Beware Of," "Houdini's Escapes," "Houdini's Magic," several in the Biff Brewster series under the name of Andy Adams, and "Judo Explained," under the name of Maborushi Kineji.)

The Shadow mysteries kept Gibson writing under pressure: He says that one time when he had to finish a chapter at Blackstone's summmer place in Michigan, friends caught and read the freshly typed pages as they rolled out of his typewriter. "That only spurred me on," he says. Another time, he says he finished a Shadow story in his Maine cabin that was literally being built around him, with carpenters hammering.

The Shadow always managed to escape from difficult situations. Trapped between two violent robots, he ducked as the robots smashed each other to bits. Another time, locked Houdini-fashion in a bridge-builder's encasement under water and, this time, looking finished for sure, The Shadow managed one of his most memorable escapes: He egged on the villain to turn up the air pressure until the case blew apart, shooting him up through the river, in one piece - and safe, of course.

Gibson says he always plotted well in advance - at least before he put paper in his typewriter. "Some writers would get to chapter 11 and have a big problem. I'd sweat it out on the plot. If I took five days when I should have taken two, I'd make it up on the writing."

Still, he'd add bits of color that occurred to him in mid-sentence. Once, as he typed, his carriage, little by little, nudged a large copper bowl further and further toward the right edge of his desk, until it fell off with a gong - just the sound he says that might occur "in the lair of Wang Foo."

Gibson says he took the names of many of his characters from railroad timetables. "If somebody said to me, 'Why did you use me for the villain in that story?' I'd say, 'Because you happen to be the third stop on the Winchendon line."

Cranston was the name of a Scottish theater owner whom Gibson came across in some notes for one of his Houdini books. There was a financier at the time named Lamont. Maxwell Holden and U.F. Grant - names which Gibson combined for his own pen name - were both New York City magic dealers.

As Maxwell Grant, Gibson made $400 for his first Shadow novel, $500 for most, and $750 near the end. "If I wanted to buy a car," he says, "I could do it with two books. But I never really did make any money. If I had invested in things like real estate, I would have come out very well. But I was so busy, so wrapped up in things.

"I didn't get as much as a typist would today for typing them. And copies of the originals are worth more gave away 10 original paintings that now than I got for writing them. I were covers . . ."

Still, he has much saved at his home - the equivalent of 22 rooms including barn and smaller house - in Eddyville, N.Y., near Kingston. "I've got a room for Shadow stuff, a room for true crime stuff, a room for magic. I've got about 30,000 books in all. All the stuff from The Great Raymond's show. I'm trying to get it organized."

The memories prompted a laugh from Gibson.

Not the laugh he made famous, the "shuddering laugh of triumph" that ended each Shadow episode.

The gentle laugh of The Shadow's creator.