The kid reaches into her backpack and pulls out a wallet. A muddy, faded, cracked leather wallet that she hands to me. “I hired a psychic, and we found this.”

“You’ve gotta be kidding,” I say, my hangover roaring back full force. “A psychic?”

“Well, before you say she’s a hack—she found something that your whole team of crime scene investigators never managed to find.” She watches me open the clasp of the wallet and sort through the credit cards and driver’s license. “It was up in a tree, on the sanctuary property,” Jenna says. “Close to where my mom was found unconscious—”

“How do you know where she was found unconscious?” I ask sharply.

“Serenity told me. The psychic?”

“Oh, well, good, because I thought maybe you had a less reliable source.”

“Anyway,” she continues, ignoring me, “it was buried under a lot of stuff—birds had been making nests up in there for a while.” She takes it out of my hands and slips from the cracked plastic photo insert the only picture still even remotely visible. It’s bleached and faded and wrinkled, but even I can see the gummy mouth of a smiling baby.

“That’s me,” Jenna says. “If you were going to run away from a child forever … wouldn’t you at least keep a picture?”

“I stopped trying to figure out why humans do what they do a long time ago. As for the wallet—it doesn’t prove anything. She could have dropped it while she was running.”

“And it magically flew up fifteen feet into a tree?” Jenna shakes her head. “Who put it up there? And why?”

Immediately I think: Gideon Cartwright.

I don’t have any reason to suspect the man; I have no idea why his name pops into my head. As far as I know he went to Tennessee with those elephants and lived there happily ever after.

Then again, it was Gideon who Alice allegedly confided in about her failed marriage. And it was Gideon whose mother-in-law was killed.

Which brings me to my next thought.

What if the death of Nevvie Ruehl had not been an accident, as Donny Boylan had pushed me to believe? What if Alice had been the one to kill Nevvie, had stashed her own wallet in the tree to make it look like she was the victim of foul play—and then run away before she could be named as a suspect?

I look across my desk at Jenna. Be careful what you wish for, sweetheart.

If I still had a conscience, I might feel a twinge about agreeing to help a kid find her mother, considering that it might involve pinning a homicide on the woman. But then again, I can play my cards close to my chest, and let the girl believe this is just about finding a missing person, not a possible murderer. Besides, maybe I’m doing her a favor. I know what loose ends can do to a soul. The sooner she knows the truth, whatever it is, the sooner she can get on with her future.

I hold out my hand. “Ms. Metcalf,” I say. “You’ve got yourself a private eye.”

ALICE

I have studied memory extensively, and the best analogy I’ve found to explain its mechanics is this: Think of the brain as the central office of your body. Every experience you have on any given day, then, is a folder being dropped on a desk to be filed away for future reference. The administrative assistant who comes in at night, while you’re asleep, to clear that logjam in her in-box is the part of the brain called the hippocampus.

The hippocampus takes all these folders and files them in places that make sense. This experience is a fight with your husband? Great, let’s put it with a few more of those from last year. This experience is a memory of a fireworks display? Cross-reference it with a Fourth of July party you attended a while back. She tries to place each memory where there are as many related incidents as possible, because that is what makes them easier to retrieve.

Sometimes, though, you simply cannot remember an experience. Let’s say you go to a baseball game, and someone tells you later that two rows behind you there was a woman sobbing in a yellow dress—but you have absolutely no recollection of her. There are only two scenarios in which this is possible. Either the incident was never dropped off for filing: You were focused instead on the batter and didn’t pay attention to the crying woman. Or the hippocampus screwed up and coded that memory in a place it should not be: That sad woman gets linked to your nursery school teacher, who also used to wear a yellow dress, which is a place you’d never find it.

You know how sometimes you have a dream about someone from your past who you barely remember and whose name you couldn’t recall if your life depended on it? It means that you accessed that path serendipitously, and found a bit of buried treasure.

Things you do routinely—things that get consolidated repeatedly by that hippocampus—form nice big connections. Taxi drivers in London have been proven to have very large hippocampi, because they have to process so much spatial information. We don’t know, however, if they are born with naturally large hippocampi, or if the organ grows as it is put to the test, like a muscle being exercised.

There are also some people who cannot forget. People with PTSD may have smaller hippocampi than ordinary people. Some scientists believe that corticoids—stress hormones—can atrophy the hippocampus and cause memory disruptions.

Elephants, on the other hand, have enlarged hippocampi. You hear, anecdotally, that an elephant never forgets, and I do believe this is true. Up in Kenya, at Amboseli, researchers have done playbacks of long-distance contact calls in an experiment that suggests adult female elephants can recognize more than a hundred individuals. When the calls were from a herd with which they had associated, the elephants being tested responded with their own contact calls. When the vocalizations were from an unfamiliar herd, they bunched and backed away.