My day ended with a ghost tour. I had arranged to meet John Lorenzen, a longtime local guide, at the obelisk that sits in the center of Santa Fe's plaza -- a memorial erected in 1868 to honor those lost in the Civil War, and also those federal troops "fallen in the various battles with savage Indians in the territory of New Mexico." The word "savage" had been chiseled away from the marble in 1973 by a guy with a blond ponytail and a hardhat, and then occasionally scratched back in, and then chiseled out again -- another contested memory from my family's golden years. I wasn't sure I'd be able to pick Lorenzen out among the homeless and skater kids milling around the plaza's center, but it was obvious from the outset that he was my guy: a sturdy fellow with brown hair and an Indiana Jones hat, leather vest, puffy-sleeved green tunic, cargo shorts, hiking boots -- the classic mufti of a New Age adventure guide.

We started at the Original Trading Post on San Francisco Street, where four basement spirits like to throw clothes from the hangers, then visited a restaurant on the site of a card room that was owned by the notorious madam Doña Tula and which allegedly brims with the ghosts of whores and gamblers. We lingered at the porch of a pretty Victorian art gallery whose previous resident, a prominent real estate agent, moved out quickly -- really quickly -- after he encountered a black-cloaked, waxen-faced figure who smelled of rotting flesh and froze all the house plants. Lorenzen believes the home is on the site of an old hanging post. Ghosts tend to congregate in places of violence, Lorenzen told me, which explains their prevalence in the once-wild West. We learned of La Llorona, an Indian beauty who married a conquistador and gave birth to two children and then, when her looks faded and her man ran off, threw her two children into the Santa Fe River, hit her head on a rock and died. She still wanders the banks of the river, which isn't much of a river anymore but rather an intermittent stream channeled and deflected and sucked away upstream -- a ghost river -- looking for other children to drown.

We ended the tour at La Posada. In the adobe reception area that now wraps the old home, we observed Abraham's gilt initials above the original entry. Then we climbed the stairs to Julia's room. It was bigger than I remembered, high-ceilinged, with a large four-poster bed. A small writing desk sat in front of the windows where, I imagined, Julia gazed out at the passing street life. There was a settee and chairs with dragon carvings that had belonged to her, and an elegant assortment of ornately trimmed Victorian furniture.

Julia had been, Lorenzen told me, an unhappy wife -- "a canary in a cage." She had, he told me, been a shut-in who killed herself with laudanum or arsenic, or may have been murdered by her husband, or the Spanish maid who loved him. Perhaps. The truth of this, like so much else, is lost to history. Lorenzen recounted stories of blankets ripped off unsuspecting sleepers and impulsive faucets. He stalked into the bathroom, which harbored an air of charming decrepitude that even a luxury resort couldn't buff away: a small-German-Jewish-person-sized bathtub, crumbling black-and-white tile. "Nineteenth-century ghosts are fascinated by plumbing fixtures," Lorenzen explained.

When the last ghost story was told, we sat in silence for a moment, and then Lorenzen cleared his throat: "Julia," he said, "if you'd like to show us a sign that you're here, we welcome it and we respect you, as the lady of the house." I looked around for a sign. "If there's anything you can do," he continued, "for our greatest and highest good, to show us that you're here, you're welcome to do so." Again, Julia didn't oblige.

After Lorenzen left, I poked around the room a bit, peering into the closet and behind the shower curtain -- for Julia, I suppose -- and then headed out to dinner and the hotel bar, which was once a family sitting room. The place was hopping. There was a jazz band, and a number of sleek people who looked like they were from Los Angeles, with sport jackets and gelled hair that crested in stiff, calculated peaks, like meringues. I sat on a velvet loveseat and ate lemon curd, observing these invaders in Julia's home, and then, when I had run out of excuses to stay, I headed up to sleep in the room where my great-great-grandmother died.

It was a restless night: glasses clinking, heaters clunking, clatter and chatter, trumpets blustering, doors closing, a dog barking in the hallway. Toward morning, I fell asleep -- and sometime after that, I woke up. Something might have happened then -- something that might have had to do with a ghost, or at least some ghostly orbs. Though really, who would believe me? It's just another story, secondhand and subjective, like all the others that link me to this home I never inhabited, this past in which I never lived. Memory is a ghost itself -- fleeting, undependable -- but it is all we have to make sense of who we are.