Several days after the Phoenix trip, Dennis and I were alone in the pool. The pool has a blue filter over the light, the spa has a red one; when the bubbles are on, it looks a little like a hot lava bath. Sometimes we talk about nothing important, sometimes we just sit silently letting the bubbles massage our skins, sometimes we stare up into the sky and watch for meteors; once we'd seen a bright red starpoint streak across the sky like a bullet.

But tonight, as he splashed in the bubbles, I found myself studying the way the light shaped his features. I'm not an expert on the development of children's skulls, but abruptly I was struck by the odd proportions of his forehead and eyes.

Before I'd adopted him, I'd been given copies of various doctor's reports. One doctor, who was supposed to be looking for fetal alcohol effects, had described the five-year-old Dennis as "an unusual-looking" child. I couldn't see what he was talking about. To me, Dennis had always been an unusually good-looking boy.

There are only two shapes of faces — pie and horse. Dennis was a pie-face, I'm a horse. In that, he was lucky because his smile was so wide he needed a round face to hold it all. He was blessed with dark blond hair which was growing steadily toward shoulder-length. His eyes were puppy-brown and hidden behind lashes long enough to trouble the sleep of mascara manufacturers. His complexion was as luminous and gold as an Arizona sunset.

His body was well-proportioned too; he had long legs and a swimmer's torso. He was thin, but not skinny. He looked like a Disney child. I expected him to be a heartbreaker when he grew up. The girls were going to chase him with lassos. Already I wondered what kind of a teenager he would become — and if I would be able to handle it.

Now… seeing him in the reflected red light of the spa — is this the same color light they have on Mars? — he did look a little alien to me. His forehead had a roundish bulge toward the crown. His cheekbones seemed strangely angled. His eyes seemed narrow and reptilian. Probably it was the effect of the light coming from underneath instead of above, combined with the red filter, but it was momentarily unnerving. For a moment, I wondered what kind of a thing I'd brought into my life.

"What?" he asked, staring back.

"Nothing," I said.

"You were looking at me."

"I was admiring you. You're a beautiful kid, do you know that?"

"Uh-huh." And suddenly he was Dennis again.

"How do you know that?"

"Everybody says so. They all like my eyelashes."

I laughed. Of course. Here was a child who'd learned to work the system. He was a skilled manipulator. He'd learned real fast how to turn on his special smile and get what he wanted out of people. Of course he knew how much attention his eyelashes attracted.

But — for a moment there, he hadn't been Dennis the little boy. He'd been something else. Something cold and watchful. He'd noticed me studying him. He'd sensed the suspicion. Or was it just the power of suggestion at work? Most of the books on parenting advised not to feel guilty for wondering if your child is going to suddenly catch a fly with his tongue. It's a very common parental fear.

And then.. whenever I had doubts about Dennis and my ability to keep up with him, all I had to do was ask myself one simple question. How would I feel if Kathy Bright said she had to remove him from my home? Ripped apart was the simplest answer. The truth was, I didn't care if he was a Martian or not, I was as bonded to him as he was to me.

But out of curiosity, and possibly just to reassure myself that I was imagining things, I logged onto CompuServe. The ISSUES forum has a parenting section. I left a message under the heading, "Is your child a Martian?"

My little boy says he's a Martian. I've heard of two other children who claim to be Martians as well. Has anyone else heard of children who believe that they're from Mars?

Over the course of the next few days — before the message scrolled off the board and into the bit-bucket — I received thirty-three replies.

Several of the messages were thoughtful analyses of why a child might say such a thing; it was pretty much what that mother in Phoenix had surmised; it's common for children to fantasize that they have glamorous origins. In the past, children might have believed they were secretly princes and princesses and one day their real parents would arrive to take them to their golden castles. But because that mythology has now been superseded by starships and mutants, it's more appropriate for children to fantasize about traveling away on the Millennium Falcon or the Enterprise. But if a child was experienced enough to know that those stories were just fiction, he would also know that Mars was a real planet; therefore… Mars gave credibility to the fantasy. Etcetera. Etcetera. Local mileage may vary, but if the delusion persists, see a good therapist. It may be evidence of some deeper problem. Etcetera some more.

I knew what Dennis's deeper problems were. He'd been bounced around the foster care system for eight years before landing in my arms. He didn't know where he came from or where he belonged.

Several of the replies I received were from other parents sharing pieces of weirdness their own children had demonstrated. Interesting, but not particularly useful to my inquiry.

But… there were over a dozen private messages.

"My sister's little girl used to insist that she'd been brought to Earth in a UFO and implanted in her mommy's tummy while her mommy was asleep. She kept this up until she was about fourteen, then abruptly stopped. After that, she wouldn't answer questions about it at all."

"My next door neighbors had a boy who said he wasn't from Earth. He disappeared when he was twelve. Without a trace. The police assumed he was kidnapped."

"My ex-wife was a child psychologist. She used to joke about her Martian children. She said she could tell how crazy New York was by the number of Martians she saw in any given year. At first she used to tell the parents that same old same old about children needing to fantasize about a glamorous background, but later on she began to wonder. The stories the kids told were all very similar. They began life as Martian tadpoles brought to Earth and implanted in the uteruses of Earth women. She always wanted to do a study on Martian children, but she could never get a grant."

"I dated a girl once who said she was from Mars. She was very insistent on it. When I tried to get serious with her, she turned me down flat. She said she really liked me, but it wouldn't work out between us. When I asked her why, she said it was because she was from Mars. That's all. I guess Martians have a rule against marrying outside their species."

"I heard about a Martian when I was in high school. He killed himself. I didn't know him. I only heard about it afterward."

"I thought I was from Mars once. I even had memories of being on Mars. It had a pink sky. That's how I knew it was Mars. When the photos came in from JPL showing that Mars really did have a pink sky, just like in my memories, I thought that proved something. When I told my parents, they took me to see a doctor. I was in therapy for a long time, but I'm fine now. Maybe you should get your son into therapy

It was the last one that really got to me. I knew the person who sent it meant to be reassuring, but instead, his message had the opposite effect.

Okay, maybe it's me. Maybe it's because I'm a writer. I read subtext where none is intended. And maybe the cumulative effect of all these messages, especially the wistful, almost plaintive tone of the last one left me with a very uncomfortable feeling.

I replied to all of these messages.

I know this sounds silly, but please indulge me. What did your Martian friend/relative look like? Did he/she have any special physical characteristics or medical problems? What was his/her personality like? Do you know what happened to him other? Does he/she still believe that he/she is from Mars?