SIOUX FALLS, SD—In light of a broken engagement two years ago, area school-bus driver and longtime conspiracy enthusiast Robert Ericsson outlined an intricate theory to reporters Tuesday to explain his failure to begin a new relationship.

"I am alone today due to the covert machinations of dozens, possibly hundreds of women in several countries," Ericsson, 38, said. "What we are looking at is a plot of epic proportions, which may seem counterintuitive, but that is, in fact, precisely what they would like you to believe."

Ericsson gathers relevant evidence on the Internet.

Ericsson said he began to suspect a "hidden hand" at work during the months following his 2004 breakup with then-fiancée Sara Osborne, when potential dates routinely refused to return his calls or e-mails.

Ericsson cites a comprehensive archive of past-girlfriend-related historical evidence that he has collected over the past 10 years. Ericsson, considered the top Robert Ericsson romantic-failure expert in the country, has spent years studying the hundreds of letters, photographs, receipts, gifts, and videotapes of himself with former girlfriends, looking for a common pattern.

The focus of Ericsson's current research is the six-day period preceding his breakup with Osborne back in March 2004.

"According to phone-company records, I called Sara at exactly 7:34 p.m. on March 8, 2004, and asked her to have dinner with me—which she agreed to do after a quick shower," Ericsson said. "Twelve minutes later, at 7:46 p.m., Sara called to say she had 'changed her mind' about dinner, but wanted to come to my apartment to 'deliver some news.'"

It was there that Osborne announced that she no longer wished to marry Ericsson.

Ericsson continued: "What happened in that 12-minute gap? What—or who—got to her? And why won't she release her phone records to me?"

Ericsson said a "coordinated, secret, high-level effort" is the only plausible explanation.

"There are wheels within wheels," he said.

Even the date, March 8, 2004, sounds alarm bells, Ericsson said. "March 8 is the 67th day in the Gregorian calendar," Ericsson said. "Pope Gregory XIII was a subject familiar to Sara, who minored in Renaissance history in college. Also, if you add the numbers 3, 8, and 2,004, you get 2,015. Add 2, 0, 1, and 5, and once again, you get 8—exactly the number of women I dated exclusively before I met Sara."

Others targeted by Ericsson as conspiracy players include a female dispatcher who works for his bus company, his mother, and a waitress he asked out three months ago. Ericsson has even traced the conspiracy to figures in the highest echelons of American society, including former Cosmopolitan editor Helen Gurley Brown, Oprah Winfrey, and the TV series Sex And The City.

Recently, Ericsson examined a newly unearthed 1997 video of him and then-girlfriend Donna Soderblum at his sister's wedding. According to Ericsson, repeated slow-motion viewings revealed a telling detail.

"See that sneer and eye-roll on Donna's face, after she turns away from me and goes back to talking to my sister?" Ericsson said. "It's all there in frames 336 through 408."

Longtime friend Keith Warren agrees that Ericsson's single status is not a fluke, but he rejects Ericsson's analysis.

Said Warren: "I explain all of Bob's difficulties in my meticulously researched and voluminously footnoted 'Lone Wardrobe Theory.'"

Ericsson dismissed Warren's analysis. "Warren's theory is interesting, but it has a long way to go in explaining why I've remained single for more than two years. There is no explanation why, for example, I am rejected by women even when I go out to bars," he said.

"Also, lots of men fit that description," he added, "including Sara's current boyfriend, Burke."

An 18-page manifesto that explains Ericsson's theory in more detail is available for free download from his website.