The scene might have emerged from the pages of a novel or folktale: a foundling, wrapped in swaddling clothes, left on a doorstep on a brisk winter afternoon.

But it happened not in another place and time, but in Northeast Washington 18 months ago. Authorities said the case of Baby Jane Doe, as they have called her, is unusual because no link to the child--no relative, no acquaintance--has been found.

Joyce E. Perry vividly remembers leaving work early March 20, 1998, and returning to the rowhouse in the unit block of Rhode Island Avenue NE that she, her two sons and her sister share.

Just that morning, Perry, 43, had been walking with DeAndre, 11, and Donnell, 7, when the boys "started fussing."

Perry recalled: "I told my older one, 'See, when I was pregnant, you said you wanted a little brother. Now why are you fussing?' He said, 'No, I wanted a little sister.' "

Hours later, Perry was watching television when her sister insisted she heard a baby's cries.

"I put the TV on mute and I kept listening, and I heard the baby crying again," Dorothy Beal, 38, recalled.

The newborn had been placed in the narrow space between the family's storm door and the inner door that opens into the house. Police, who arrived at 5 p.m., a few minutes after the sisters called 911, found the child wrapped in a knitted white blanket with a sky blue and orange-pink border. She was dressed in a white one-piece sleeper.

The baby, who doctors estimated was 5 days old, weighed 5 1/2 pounds, and the police report noted that she was "crying but consolable."

She was taken to Children's Hospital, found to be in good health and transferred to St. Anne's Infant and Maternity Home in Hyattsville, according to Lt. John R. Alter, of the D.C. police department's youth and preventive services division.

But Baby Jane's delivery to safety was only the start of an intense but unsuccessful search for any link to her relatives or to her brief past.

A 1990 U.S. Justice Department study found that 14,500 children were abandoned in this country in 1988, the latest year for which data are available. A slight majority, 51 percent, were 4 or younger, the study found.

Although as many as 20 to 25 children are reported missing each day in the District, intentionally abandoned infants or children are unusual, Alter said. In those cases, detectives usually can track down a parent or acquaintance soon after, he said.

Baby Jane is one of just two unidentified, abandoned infants known to the National Center for Missing and Exploited Children, said Julia Cartwright, a center spokeswoman. The infant is one of six missing, abducted or abandoned D.C. children profiled on the center's Web site (www.missing kids.org).

"This is a rare occurrence," said Alter, who is in charge of reports of missing persons and abused or neglected children in the District.

Seven detectives from the youth division worked on the case, canvassing the block for anyone who might have seen or heard of a woman who might recently have given birth.

Mail carriers and business people were interviewed as well.

Police called hospitals from Annapolis to Richmond, asking whether an expectant mother might have crept out unusually early.

Because some placental fluid was found in the baby's hair and some blood was found on her blanket, police do not believe the infant was born in a hospital, Alter said.

Police also do not believe the baby was left on Perry's doorstep for any particular reason. "Mom probably panicked and dropped it off with someone halfway decent in the block, thinking: Hey, they'll get them to the right authorities," Alter said.

Beal said she and her sister wracked their memories trying to think of anyone who might have left the baby on their stoop. "My sister, myself and the two boys are the only ones here, and we don't hardly go outside too much, and the neighborhood is pretty quiet," Beal said.

The sisters said they toyed with the idea of keeping the infant but rejected it because they believed she needed medical attention and because it would be important for authorities to be able to search for her family.

"We would have loved to have kept her," Beal said, laughing. "She was so pretty. Very beautiful."

Police said the D.C. Child and Family Services Agency has placed the infant in preadoptive foster care.

If the child is adopted, the investigation would be suspended, but Alter said Tuesday that the case is actively open and that police are searching for leads.

He urged anyone with information on the case to contact the youth division at 202-576-6768 or 202-576-6771.

Alter said the mystery of who left the baby is one of the most baffling he has seen.

"My sixth sense is that it might have been someone from out of town, in transit, who left the baby and continued on," Alter said.

"I'm a father myself," Alter said. "You'd really like to link [the baby] back up even if the parent didn't want the child," he said, noting the importance of knowing the medical history of a child's biological parents.