This is the boy whose mother left a message on the answering machine at the professor’s house. The boy whose name is entered into Jess’s schedule on the day she disappeared.

“Professor,” I say, “you wouldn’t happen to know where he lives?”

Jacob Hunt and his family reside in a part of Townsend that’s a little more run-down than the rest of it-the part you have to work harder to find behind the picture-postcard town green and the stately New England antique homes. Their house is just beyond the condos that are filled with the recently separated and newly divorced, past the train tracks for an Amtrak route that’s long defunct.

The woman who opens the door has a blue stain on her shirt and dark hair wound into a messy knot and the most beautiful eyes I have ever seen. They’re pale, like a lioness’s, nearly golden, but they also look like they’ve done their share of crying, and we all know that a sky with clouds in it is much more interesting than one that doesn’t have any. I’d place her in her early forties. She’s holding a spoon, which is dribbling its contents onto the floor. “I don’t want any,” she says, starting to close the door.

“I’m not selling anything,” I say. “You’re, um, dripping.”

She glances down, and then sticks the spoon into her mouth.

That’s when I remember why I’m here. I hold up my badge. “I’m Detective Rich Matson. Are you Jacob’s mother?”

“Oh, God,” she says. “I thought he’d already called you to apologize.”

“Apologize?”

“It’s really not his fault,” she interjects. “Granted, I should have known that he was sneaking out, but with him, this hobby is almost a pathology. And if there’s any way I can convince you to keep this quiet-not a bribe, of course, just maybe a handshake agreement… You see, if it becomes public knowledge, then my career could really take a hit, and I’m a single mom who’s barely scraping by as is…”

She is babbling, and I have no idea what the hell she is talking about. Although I did hear the word single. “I’m sorry, Ms. Hunt-”

“Emma.”

“Emma, then. I… have no idea what you’re talking about. I came because your son is tutored by Jess Ogilvy-”

“Oh,” she says, sobering. “I heard about Jess on the news. Her poor parents must be frantic. Are there any leads yet?”

“That’s why I’m here to speak to your son.”

Those eyes of hers darken. “You can’t possibly think Jacob had anything to do with her disappearance?”

“No, but he was the last appointment in her date book before she disappeared.”

She folds her arms. “Detective Matson, my son has Asperger’s syndrome.”

“Okay.” And I’m red-green color-blind. Whatever.

“It’s high-functioning autism. He doesn’t even know Jess is missing yet. He’s had a hard time lately, and the news could be devastating to him.”

“I can be sensitive about the subject.”

She measures me for a moment with her gaze. Then, turning, she heads into the house, expecting me to follow. “Jacob,” she calls as we reach the kitchen.

I stand in the entryway, waiting for a child to appear. After all, Jess Ogilvy is a teacher and Professor Gorgona referred to a boy she worked with. Instead, a behemoth teenager who’s taller than I am, and probably stronger, shuffles into the room. This is who Jess Ogilvy tutored? I stare at him for a second, trying to place the reason he looks so familiar out of context, and suddenly it comes to me: hypothermic man. This kid identified the cause of death before the medical examiner did.

“You?” I say. “You’re Jacob Hunt?”

Now his mother’s rushed apologies make sense. She probably thought I’d come to slap a fine on the kid, or arrest him for interfering with a crime scene.

“Jacob,” she says drily, “I think you’re already acquainted with Detective Matson.”

“Hi, Jacob.” I hold out a hand. “Nice to officially meet you.”

He doesn’t shake it. He doesn’t even look me in the eye. “I saw the article in the paper,” he says, his voice flat and robotic. “It was buried in the back. If you ask me, someone dying of hypothermia is worthy of at least page two.” He takes a step forward. “Did the full autopsy results come back? It would be interesting to know if the alcohol lowered the freezing point for the body, or if there’s not a significant change.”

“So, Jake,” I say.

“Jacob. My name is Jacob, not Jake.”

“Right, Jacob. I was hoping to ask you a few questions?”

“If they’re about forensics,” he says, growing animated, “then I am more than happy to help. Have you heard about the research coming out of Purdue, on desorption electrospray ionization? They found that the sweat from finger pores slightly corrodes metal surfaces-anything from a bullet to a piece of a bomb. If you spray the fingerprints with positively charged water, the droplets dissolve chemicals in the fingerprints and transfer minute amounts that can be analyzed by mass spectrometer. Can you imagine how handy it would be to not only get fingerprint images but also identify the chemicals in them? You could not only place a suspect at a crime scene but also get proof that he handled explosives.”

I look at Emma Hunt, begging for help. “Jacob, Detective Matson needs to talk to you about something else. You want to sit down for a minute?”

“A minute. Because it’s almost four-thirty.”

And what, I wonder, happens at 4:30? His mother doesn’t react at all to his comment. I feel a little like Alice in Wonderland, in the Disney video that Sasha likes to watch on her weekends with me, and everyone is in on the Unbirthday routine but me. Last time we’d watched it, I realized that being a parent wasn’t all that different. We’re always bluffing, pretending we know best, when most of the time we’re just praying we won’t screw up too badly.

“Well, then,” I say to Jacob. “I guess I’d better start.”

The only reason I let Rich Matson into my house is because I’m still not entirely sure that he doesn’t want to punish Jacob for showing up at his crime scene last weekend, and I will do whatever I have to do to make that whole nightmare go away.

“Jacob,” I say, “Detective Matson needs to talk to you about something else. You want to sit down for a minute?”

We are racing against a clock, not that Matson would understand. “A minute. Because it’s almost four-thirty,” Jacob tells me.

I don’t know how anyone could look at Jacob and think he’d be a viable witness. Sure, his mind is a steel trap. But half the time, there’s no lock to get inside it.

The detective sits at the kitchen table. I turn down the flame on the stove and then join him. Jacob is struggling to look in Matson’s direction, but his eyelids keep fluttering, as if he’s staring into the sun, and finally he gives up and lets his gaze slide away.

“You have a friend named Jess, right?” the detective asks.

“Yes.”

“What do you and Jess do together?”

“We practice social skills. Conversations. Good-byes. Things like that.” He hesitates. “She’s my best friend.”

This doesn’t surprise me. Jacob’s definition of a friend isn’t legitimate. To him, a friend might be the kid whose locker is next to his in school, who therefore has an interaction at least once a day to say, Could you move over? A friend is someone who he’s never met but who doesn’t actively taunt him in school. Jess may be paid by me to meet with Jacob, but that doesn’t take away from the fact that she honestly cares about him and connects with him.

The detective looks at Jacob, who, of course, is not looking at him. I watch people falter over that normal courtesy of communication all the time-after a while, it feels like staring, so they look away from Jacob, mirroring his behavior. Sure enough, after a moment, Matson stares down at the table as if there’s something fascinating in the wood grain. “Right now, Jacob, Jess is missing. And it’s my job to find her.”