Marc Salem's remarkable head resembles an egg in a nest. His dark-brown beard curls around his jaw like supple twigs, but on top he is entirely bald. Perhaps his brains pushed out all his hair.

Genetics aside, it seems plausible that the thoughts ricocheting back and forth inside Salem's finite and hard dome would have some physical manifestation. It certainly seems no more impossible than the way that Salem, a former Baltimorean, makes a living: reading people's thoughts.

At least, in the five years since he has been publicly performing his one-actor show, Mind Games, no one has come up with an explanation as to how Salem can correctly call out a serial number on a $10 bill without touching it, and while wearing coins taped over his eyes and a blindfold. Or how he did this:

On the stage at the Gordon Center for Performing Arts, Salem, still blindfolded and a bit impatient, waits while volunteers collect personal items belonging to other audience members. The stage is elevated about three feet above the theater floor, and every step that Salem takes brings him a bit closer to danger. And he takes several steps. This is a man who seems to have a hard time keeping still. Perhaps he likes literally living on the edge.

Finally, an item is brought up. Salem floats his hand about a foot above it, and asks the unknown owner to say out loud, "This is mine."

A woman in the audience complies. Salem's response comes rapid-fire.

"This is a rectangle, a case," he says, "An eyeglasses case. And the glasses are in it. You aren't wearing them, are you? Your left eye is weaker than your right eye, and the prescription is 60/20. And the name on the glasses case, the company that manufactured it is ... Smith."

"I don't know," the woman replied, "I can't read it without my glasses."

Everyone laughs. And almost before the volunteer on stage has time to confirm Salem's statements, he's floating his hand above the next object, a crutch, which as it turns out, is made by a company called Methodic Mobility Systems Inc.

So captivating is Salem's act, it seems a pity that he is in town for one show only, a performance honoring the 80th anniversary of the Center for Jewish Education. Salem's brother, Chaim Botwinick, is the group's executive vice-president, so Salem (his stage name) flew in one afternoon late last month from London's West End, where Mind Games has won popular and critical acclaim, as it did in Toronto, and before that, off-Broadway. He has been featured on Rosie O'Donnell and Maury Povich's television shows and on CNN, and his work has been written up in such publications as the New York Times and the London Times.

In the future, he hopes to create a series for educational television, perhaps for PBS, with whom he says he's negotiating. For each show, he would perform one of his mind games, and an expert would explain how he did it.

"I'm very excited about it," he says. "It seems in retrospect that this is where I've been heading ever since I've been on a career path, even though I didn't know it at the time."

Until a few years ago, the 49-year-old Salem taught communications at Marymount Manhattan College in New York. Previously, he had been a director of research for Sesame Street. He's done television commentary on the nonverbal testimony of O.J. Simpson and former President Bill Clinton, he helps attorneys select juries, and he says Pulitzer Prize-winning playwright and director Arthur Miller has hired him as a consultant to fine-tune actors' body language.

Drawing on techniques grounded in mathematics, psychology and advertising, Salem claims to use no audience shills or hidden electronic devices, and has publicly offered a $100,000 reward to anyone who can prove otherwise.

How then, to account for a crisis counselor named Sheila? There she is, sitting quietly in her seat about halfway back in the auditorium when Salem asks her to first visualize a vase, and then to visualize the price of that vase.

After a moment she says, "two-fifty."

"Is that two-hundred fifty dollars and no cents?" he asks.

"That's right," she says.

Salem pulls a piece of paper from his pocket and asks Sheila to read it aloud.

She gasps, and after a moment she speaks: "It says, 'This vase is worth $250.' "

The rest of the show contains other such "wow!" moments, some with more exclamation points than others.

Part of the show uses such well-documented, if imperfectly understood, scientific phenomena as biofeedback. (At one point, Salem makes his pulse slow to a crawl, then race forward, then seemingly stop, according to the testimony of an astonished doctor taken from the audience.)

Part of the show relies on Salem's mastery of nonverbal communication. (He uses body language to correctly match a series of drawings with the audience members who sketched them).

And part depends on the power of suggestion. (He influenced Sheila - somehow - to select a price for the vase that he'd written down in advance. )

And yet, Mind Games seems fundamentally different from the magic shows done by, say, David Copperfield. The pleasure of the latter lies in knowing in advance that you're going to be duped, and appreciating the finesse with which the magician does exactly that. Salem's show has elements of trickery, but it also has elements of something else.

"It goes far beyond sleight-of-hand," his brother Chaim Botwinick says.

But where, exactly?

The mind's potential

On the afternoon after Salem's performance, the international terminal at BWI is vast and bright and empty, like the deck of a ship.

Salem is tired - very, very tired. He has been in Baltimore for exactly 27 hours to do the benefit appearance for the Center for Jewish Education (he waived his fee) and is on his way back to London, so his east-to-west jetlag is smashing headlong into his west-to-east jetlag.

He hadn't anticipated this interview and isn't entirely happy about it. This is a man who makes his living reading other people's body language, but at the moment, it's not difficult to read his. He chooses to conduct the interview in a setting that emphasizes the awkwardness of the encounter: sitting side-by-side on a bench, so that he and his interrogator have to twist their bodies to face one another.

For Salem, the subliminal cues that he picks up on are as real and tangible as the bench, which is made of perforated metal and shaped like waves. He insists that he's not a mind-reader --- he objects to the intrusive connotations of that phrase. The most that he will plead to is "a thought-reader, because thoughts can be guided by misdirecting the audience."

Here are some words that he does not want associated with him: Psychic. Telepathy. The occult. Supernatural. ESP. He will allow "intuition," but hesitantly. "What I do is entertainment," he says. "I just use the potential of the mind to have a good time."

Perhaps Salem resists labels that would set him apart, keep him at a distance from the rest of us. Imagine how lonely that could feel. And besides, if Salem were to claim extraordinary powers, that would imply that they were beyond the reach of ordinary human beings - a tenet he staunchly denies.

"We're living in a world that's giving us signals all the time," he says. "Eighty percent of all communication is nonverbal. Too often, we ignore the information that's all around us, the nuances of things. Calling it extrasensory perception is ridiculous. It's part of our senses."

And yet, for someone so interested in debunking any vapors of mysticism that might cling to his show, he is oddly reluctant to provide the concrete proof - a specific explanation of what he does. Salem is short, has rounded contours and on the day of the interview was dressed entirely in black.

Trying to persuade him to describe his methods in any detail was a bit like trying to use the power of positive thinking to deflect a bowling ball hurtling down the lane. Perhaps it's not surprising that someone who directs other people's thoughts is himself not overly amenable to suggestion; in comparison, your own will can feel like a puny thing.

"This isn't the time or the place, and it's not something I can explain in just a few sentences," he says. "I talk about these things in the classroom, but the show is the entertainment part of my life, and it's separate from the academic part of my life."

It may be, too, that Salem himself doesn't always know how he does what he does. Perhaps he can't explain it.

"Sometimes things will happen during the show, and afterward I have no memory of them whatsoever," he says.

"But that doesn't make me psychic, and it doesn't make me unique. There are physicians who can shake your hand and instantly know what's wrong with you. Maybe they've noticed that your cheeks are flushed. Or maybe even they don't know how they know."

What comes naturally

Marc Salem was born Moshe Botwinick, the son of a prominent Philadelphia rabbi and a pharmacist, and the second of three boys. (Chaim is the oldest; the youngest brother, Avi, is a speech therapist in Philadelphia.)

Even as a 10-year-old boy, Marc had unusual abilities.

"We would be in different rooms, and Marc would tell me to concentrate," Chaim Botwinick says. "Then he would come in and tell me what I had been thinking. Or he would send me into a different room and tell me to write down a few words, and he would know what I had written. He never told me how he did it, and I don't think I ever asked him."

In the late 1960s, Marc moved to Pikesville, where he studied and boarded at the Talmudical Academy of Baltimore. (He seemed delighted that some of his former classmates attended the show.)

This intellectually gifted son of intellectually gifted parents seemed destined for a career in academia. He did graduate work at the University of Pennsylvania and New York University, and began performing his mind-reading games at parties to pick up extra cash.

After working for Sesame Street, he eventually began teaching at Marymount. Now the father of three young boys, Salem built a lucrative second career moonlighting as the entertainment at corporate events. One was attended by a New York producer who, he says, "asked me if I could do what I had just done off-Broadway, eight times a week."

Could he ever.

Since 1997, he's been playing to rave reviews and sold-out houses. The plaudits he has received are pleasant, but bewildering. "It boggles me a little," he says. "To me, it borders on the inexplicable."

After all, he's just doing what comes naturally. He's just doing what each and every one of us could do, if only we studied as long and as hard as he has.

Or so he says.