We trotted up half a dozen steps and were passing through the glass doors when Murphy said, “We’ll be scanned by security just inside. I hate them being here, raising people’s anxiety level in a place where we want them to feel safe. But all new arrivals pass through here, and someone decided it was a good idea.”

Thinking about the illicit-substance and weapons scans in all the airports and public buildings back home, I raised my eyebrows. “What’s it for?”

“To get a sort of fingerprint on everyone,” he explained, walking through the doorframe-shaped scanner. “Just to make sure we know who’s who. They can’t do it at the transport terminal because no one has ghosts when they first arrive.”

I followed him through the scanner, and a long beep sounded somewhere off to my left as I joined him inside. Murphy’s head jerked toward the sound. His eyes moved to the glass doors we’d just come through, and slowly back to me. He glanced at the security desk on our right.

“Where is it?” Murphy called to the guard, whose fingers were flying over his keyboard. The guard’s ghost leaned against the wall behind him, little more than a shadow.

The man stopped typing and looked up. “I’m sorry, Dr. Murphy?”

“I heard the alert go off, but I don’t see her. My ghost, Simon,” Murphy added, growing impatient. “Do you see her?”

The guard blinked at him a couple times. Then he cleared his throat. “She’s standing right next to you, Dr. Murphy.”

* * *

Murphy looked at me, startled. He shook his head and walked over to the security desk.

I turned halfway around, searching for the missing Aunt Maeve.

Though the colonists were far from any real understanding of the aliens, Ardagh 1’s scientists had established that they were nearly identical to us physiologically. Only a specialized medical scan could reveal the differences in their insular cortex and limbic structures.

So the security scan was identifying ghosts””creating a record to help keep track of who was and wasn’t human. I joined Murphy at the security desk, and the guard swung the display around so Murphy could see it.

The screen was split into two halves, a picture of me filling one side. Opposite the photo was a crisp 3-D brain scan. Murphy touched the screen to manipulate the image, zooming in on a half dozen small, flashing red patches. He dropped his hand and stood staring at the screen.

“No question, Dr. Murphy,” said the guard. “This has never happened before. I’ll have to file a report, and I’ll need to do a full workup on this new one. My shift is over at three. Do you have time then for me to ask you some questions?”

Wait. One. Minute. The guard’s face wheeled as the ground lurched under my feet.

My first case of space-voyage induced jet lag had taken a toll on my processing ability, but I was pretty sure all of this was adding up to a dangerous misunderstanding. I fixed my eyes on the man most likely to clear it up.

“Murphy, what’s going on?”

“Come with me,” he said, nodding toward the entrance.

I followed him between the desk and scanning equipment, stopping just inside the doors. He walked slowly back through the scanner, and I did the same””flinching as another beep sounded off to my left.

By the time we got to the security desk I was shaking.

“Same as before, Dr. Murphy.” The guard spun the display around and we were again looking at the split screen. The woman in this new photograph wore a worried expression.

My heart raced. I flashed hot and then cold. Calm down. Use your head and get to the bottom of it.