Mary Ellen Pleasant lived in a large mansion in San Francisco known as the "House of Mystery." It was not as mysterious as she was. Her autobiography, dictated in 1902, only widens an obscure void. Pleasant was elusive; she was either a heroine or a villainess, no one knows for sure. She amassed great wealth and lived to a ripe age of 90. Other than that, her story is slippery and mythical. Historians are no closer to unearthing the real woman from the dusty cloak of time than biologists are at finding Nessie in Loch Ness. Pleasant claimed she was born in Philadelphia in 1814 to free parents. Many of her contemporaries contended she was born as a slave near Augusta, Georgia, to a white father and a black mother -- a voodoo princess from Santa Domingo.