I walked over. The camera was mounted directly over a dentist’s office. The hours were listed on the door, including ten to one on Saturdays. Inside, a half dozen people were sitting in the waiting room. A mom and a boy of about ten were talking to a middle-aged woman in scrubs seated behind the reception desk.

I went inside and waited impatiently while the mom consulted her phone, rejecting date after date for a follow-up appointment for her kid. Finally they settled on one, and it was my turn.

“Checking in?” the woman asked. Her name tag read MACY. She clicked a key on her keyboard.

“Actually, I wanted to ask if that’s your security camera outside?”

Macy’s attention was still on her screen. “Yeah. We were having a problem with thefts. Drug addicts looking for painkillers, and then they’d steal anything that wasn’t nailed down.”

“I take classes at that kung fu school downstairs. A student went missing after class Thursday night. Her name’s Savannah. I saw her go up those stairs, but she never made it home.”

Macy’s eyes flashed up to mine. A blue light started blinking on her desk, but she ignored it.

I raised Savannah’s beanie. “This is her hat. I just found it caught in the blackberry bushes outside. I think something happened to her in your parking lot.”

Before Macy could say anything, a man wearing scrubs and latex gloves appeared behind her.

“Macy! I need you back in room three to explain Mrs. Olsen’s options to her.” Without waiting for an answer, he turned on his heel.

“Yes, Dr. Yee,” Macy said, getting up. She looked at me. “That camera just films the sidewalk in front of the door. Nothing else.”

“Wait,” I said as she started to leave. “Just tell me, does it run all the time?”

“Yes, but the memory only holds forty-eight hours’ worth of video. After that, it records over it.” She went down the hall.

Maybe Macy was hoping I would disappear while she was gone. Just like that footage would disappear tonight.

While I was waiting for her to return, my dad pulled up in his unmarked Ford Explorer. I went outside and told him what was going on.

“This is Savannah’s hat.” I held it out. “I saw her putting it on right after class Thursday. So how did it end up in those bushes?” I pointed.

“How can you be sure it’s hers?” He looked skeptical. “Everyone’s got one of those.”

“Maybe so, but this one has a clump of long, dark hair. Just like Savannah’s. It looks like it was pulled out.” Thinking about it made me feel like I’d gotten a side kick to the ribs.

Instead of directly taking the hat, Dad opened his trunk and got out a brown paper bag with EVIDENCE printed on the top in black block letters. He filled out the form on the front, then pouched it open and had me drop the hat inside.

After he put the bag in his trunk, we walked back into the dentist’s office together. Before, I’d been practically invisible because I was a teenager. I still was invisible, but now it was because I was standing next to a man in a dark uniform with a badge on his chest, a Glock on one hip, and a Taser on the other. The waiting patients did not bother to hide their stares as they tried to figure out why he was there.

And my dad’s presence changed everything for both Macy and Dr. Yee. After a brief whispered consultation, we were allowed into a small file room to view the video feed from the security camera. Well, initially my dad suggested that I head home while he watched it, but I refused, and he didn’t argue.

But when Macy pulled up Thursday night’s video on a computer monitor, I saw that she was right. It showed just the space directly in front of the door. Only the very edge of the frame captured a slice of the darkened parking lot. It didn’t even reach as far back as the blackberry bushes.

After showing my dad how to move the video forward and backward, how to speed it up and slow it down, Macy left.

“Okay, what time did class end Thursday?” Dad asked.

“Seven thirty, and then Savannah and I mopped the floor. We probably left the dojo at seven forty-five.”

“I’ll start at seven thirty just to be sure.” He set it to run at high speed, which meant that every ten seconds was collapsed into one. While it played, his finger hovered over the pause button, ready to hit it as soon as we saw something.

Only we didn’t. The image never changed. A dark empty space. Not even a leaf or a piece of litter blew through.

As we watched and waited, I knew I had to bring up what I’d heard after I left his office. “I was asking around at school yesterday. Somebody said that earlier this week Courtney Schmitz thought a guy was driving real slow behind her on the way home from school. And about six weeks ago, Sara Ratliff was talking about something similar.”

“What?” My dad hit the pause button and turned toward me. “And you didn’t think to tell me until now? Don’t you understand, Daniel? I am responsible for students’ safety. And now you’re saying that you were aware students were in danger and you did not inform me?” He wasn’t raising his voice, but it still sounded like he was yelling.

“But I didn’t really know, not until now. I only heard about Sara secondhand, and I didn’t learn about what happened to Courtney until yesterday. And you know Sara. Courtney’s just the same. They both like to be the center of attention, even if that means exaggerating things. I’d figured Sara was probably imagining it. Besides, the two cars weren’t even the same.”

“You’re sitting there saying that when an actual girl has gone missing?” He made a frustrated growl. “That’s not for you to say, Daniel. You let me be the judge of things like this. What about the driver? What did Courtney and Sara say he looked like?”

“I guess they said the windows were all steamed up so they couldn’t see inside. About all they could tell was that the driver was a man.”

Shaking his head, my dad turned away and pressed the button again. “If you’d told me back when it happened to Sara, we might have had a lead now. We might have had a name. But we’ve got nothing.”

Was my dad right? Should I have run to him with second- or thirdhand information about Sara? “Even if some guys have been slowing down and looking at girls walking to school, creeping them out—I know that’s not a crime.” I threw my memory of past conversations back at him. “You’re always talking about how you need to have something that will be prosecutable in a court of law.”

He swore. “Well, now we’ve got nothing. Nothing about those cars, and nothing on this tape.” I looked where he was—at the clock on the video: 8:30. A full forty-five minutes after Savannah should have come up the stairs.

Whatever had happened must have been out of reach of the camera. In the dark. No witnesses, not even a digital one.

Macy stuck her head in the door. “Any luck?”

“No.” My dad turned back to the computer, ready to turn the video off.

And that was when we saw it.

Two feet entered the top corner of the frame. Savannah’s. I didn’t just recognize her shoes but the graceful way she moved.

Then behind her feet, two more appeared. Wearing what looked like work boots, although that was just a guess, because the lower legs were covered by dark coveralls. And suddenly the big feet were right behind Savannah’s, so close the tips of his boots must have been hitting the heels of her worn Vans.