The man she wanted - and finally found and nicknamed "Slowhand" - would have to indulge her in a special way: by torturing her sexually and then snuffing out her life.
This is the extraordinary scenario being described by investigators who found Ms Lopatka's body a few days ago in a shallow grave beside the mobile- home residence in North Carolina of a man named Robert Glass.
Mr Glass, 45, is now in custody, facing charges of premeditated murder.
The daughter of a prominent rabbi in Baltimore, Maryland, Ms Lopatka, 35, ran a small classified advertising business from her own web-page on the Internet.
Adopting the name "Nancy" for herself, she is believed to have started her search for Mr Right several weeks ago by entering a so-called "Chat Room" dedicated to exchanging sexual fantasies with other Internet users.
Among the themes discussed in such rooms are "master-slave" sexual role- playing.
Mr Glass - or Slowhand - was apparently the second person to have received her unusual request. While Ms Lopatka's first correspondent declined, Mr Glass, a computer operator for his county government, did not and agreed to a meeting at his home.
According to police charges filed in a North Carolina court, Ms Lopatka exchanged roughly 800 pages of e-mail with Mr Glass before leaving her home in Maryland on 13 October. She left a note to her husband that read: "If my body is never retrieved, don't worry, now that I'm at peace."
She is believed to have then taken the train from Baltimore to Charlotte, North Carolina, in the full knowledge that she was travelling to almost certain death.
"She went to see him; she stayed with him; she was not there against her will," the local North Carolina Sheriff, Roger Hutchings, told reporters.
An initial post mortem on Ms Lopatka's body produced evidence which suggested that she had been strangled.
The case was cracked when, on 20 October, Ms Lopatka's husband filed a missing persons report with the local police. On a first visit to the couple's home, a detective spotted the computer in the home and learned of her use of it.
The husband agreed to allow the computer to be taken to the police station, where some of the e-mail messages between Nancy and Slowhand were discovered. They were able to track down Mr Glass to North Carolina through his e- mail address.
The language used in the e-mails are described simply as "vulgar" and "dirty" by police. A police affidavit filed in court states: "Additional e-mail messages described in detail how Slowhand was going to sexually torture the missing person and ultimately kill her."
Ms Lopatka had apparently told family members that she was leaving to visit friends in Georgia.
The note left behind also said, according to the affidavit, that she "was not returning and asked her husband not to go after the one who did this to her."
Married but separated, Mr Glass advertised himself on the Internet with his own home page, which presented a picture of himself and descriptions of his interests.
Child pornography and white-collar crimes such as fraud and embezzlement are increasingly being committed via the Internet.
As far as the authorities in Maryland or North Caroline are aware, however, this is the first such case of a victim soliciting her own demise via e-mail in cyberspace.