The sign advertising "Free Stress Test" beckoned Marian Prescott as she crossed Farragut Square, and she found herself settling into a chair beneath a yellow tent and taking hold of two metal poles hooked up to a device that the tester said could detect psychic strain.

"What did you think of?" asked Kelly Turrisi, the tester, as the needle on the electrometer jumped to the right.

Prescott tilted back her head and laughed. Work. Her husband. What else?

Turrisi, 19, leaned forward, her eyes concealed by oversize black sunglasses that matched her black outfit. She asked Prescott a few more questions. Did she and her husband argue a lot? What was happening at her job? What was happening in her life that she most wanted to change?

Then Turrisi handed Prescott a paperback book, "Dianetics" by Church of Scientology founder L. Ron Hubbard, the back of which promised advice for living without "insecurity, negative thoughts, depression and irrational behavior." All Prescott needed to own this trove of wisdom was to fork over the "suggested" donation of $8.

"It's an amazing book," promised Turrisi, reciting the names of a few famous Scientologists, including John Travolta and Isaac Hayes, as well as Tom Cruise, whom she described as "one of the most well-known actors on the planet."

Prescott, 40, a management consultant who lives in Olney, had expected a test to check her blood pressure or her heartbeat when she sat down. A book? About Dianetics? She put her hands up to her face and shifted in her seat.

The pitch was, well, stressing her out. She stood up and went on her way.

Unfazed on that afternoon last week, Turrisi waited for her next subject. She and her colleagues, all employees and volunteers at the Founding Church of Scientology, retain an unceasingly sunny disposition as they staff their booth, which for the past six months has made appearances at Dupont Circle, a few blocks from the church's 20th Street headquarters, and Union Station, Farragut Square and the Springfield Mall in Northern Virginia.

The Rev. Susan Taylor, the D.C. church's president, said the stress test is a way for the organization to spread the message of Scientology, a faith movement that acolytes have lauded for helping people gain control of negative emotions but that skeptics have dismissed as a cult. "It goes back to" the Sept. 11, 2001, terrorist attacks, said Taylor as she retreated from the table to the shade. "After 9/11, it was realized by many people the amount of stress is incredible, and we feel we have some tools that can be beneficial."

Among those tools are the electrometers, which come with an array of dials and a roving needle. Taylor described the device as a "religious artifact used as a spiritual guide," not a "psychological or scientific instrument."

"It helps them focus on something," she said of how people benefit from the test.

At that moment, Alex Lemon, 19, a deputy in the church's marketing department, stood on the sidewalk trying to attract some of the lunch-hour crowd. Most passersby did not break stride as they smiled vaguely at his invitation: "Hello, sir, would you like a stress test?"

"I'll break your meter" is the response Lemon said he often hears.

Up stepped Hashim El-Tinay, 58, the head of a D.C.-based foundation dedicated to studying Africa and the Middle East. After handing El-Tinay the poles, Lemon asked him what he was thinking about.

His mother and father, his sisters and "various" girlfriends, El-Tinay answered. And another thing: "I'm thinking about how stressed you are to find out how stressed I am," he said, chuckling.

Ella Capaldi, a paralegal who lives in Columbia, sat with another tester, Astrid Reeves, 37, who asked her to think of things that cause her stress. The needle jumped to the right.

"I haven't focused on anything," Capaldi protested.

Reeves smiled.

Capaldi said she loves her husband. They had just returned from vacation. Work, she said, "is a piece of cake." Everything was swell, except for the fact that she has to wake up in the morning to go work. "That's a pain in the behind," she said. She passed on the offer to buy the book.

A few minutes later, Kenny Blake, 24, a Shaw resident who works at a commercial laundromat, slipped into a chair, across from his tester, Terry Dechaunac, who sells antique rugs when he isn't volunteering for the church.

"You got some stress you want to tell me about?" Dechaunac asked.

Blake smiled. "You know that," he said, mumbling about his relationship with a former girlfriend.

Dechaunac reached for a copy of "Dianetics." Blake took a look at the back, then announced, "I don't have no eight bucks. That's why I have stress. I don't have money."

That was a fib, he confided after strolling away. He had the money, just not the interest. "Everybody goes through stress," he said with a shrug. "You just got to deal with it."

Maria Hill administers a stress test to Nkosi Aqize at the Church of Scientology's public booth in Farragut Square.