My latest client was a short bald guy in a pinstripe suit. He had knobby hands, smooth green skin, antennae and eyes like silver dollars. He wore an “I Like Ike” button on his left lapel — a good private detective notices things like that.

“My name is John Doe,” he began. “I am a shoe salesman from New Jersey.”

The story fit, but somehow I just couldn’t buy it. My brain shifted into high gear as I drew on my five years of experience as a private eye and ten as a busboy at the Brer Rabbit Motel. Then it hit me: He spoke English well — too well, and with a slight fourth-dimensional accent to boot. A foreigner for sure.

“I am looking for my wife,” he said.

“That’s unusual.”

“She disappeared a week ago. That is all I know.”

“Can you describe her?”

He took out a photo and casually flipped it in my direction. It stopped in mid-air and hovered about a foot in front of me. I think I jumped a little when I saw the face. Mrs. Doe was bald with green skin, antennae, and eyes like silver dollars.

“Are you sure you want me to find her?”

He snatched the photo back. “Will you take the case,” he asked evenly, “or shall I go somewhere else?”

Good question. The more I talked to this guy, the less I liked him. He was cool as a cucumber — about the right color, too. There was a gleam in his eyes that made me glad I had a .38 in the top drawer, just behind the family-size bottle of rye. That reminded me: the bottle was about half empty. That would never do.

“Sure, I’ll take it,” I replied, “for a price. Two hundred bucks a day plus bus fare.” I figured his bank account was no bigger than he was.

“Agreed. I will return tomorrow to check on your progress.” He walked out.

He was pretty interesting for a midget, and I guess my curiosity got the better of me. I pocketed by gun and followed, quietly. He left the building and walked straight towards the bad side of town. I tailed him unobtrusively, stopping every so often to look up at the sky or pretend to take a stone out of my shoe.

After a few blocks he met a woman on a street corner. She didn’t look like his wife. She didn’t look like anybody’s wife. They went around the corner to the Seven Sins, a seedy little nightclub known for its sloe gin and fast women. The place was packed with the dregs of humanity: drunks, hookers, battered wives, battered husbands, retired schoolteachers — you know the type.

I pushed through the crowd and took a seat near my client. He was sitting alone, but I didn’t wonder why for long. Some canned music started playing too loud, and suddenly his friend appeared on stage in a natural pink outfit. It was worth seeing. Luckily I had gotten used to that kind of thing years ago, but you could see it was new to the little guy. His eyes popped out as if they were flying from a slot machine, did a dance in time with the music, then popped back in again so as not to miss the finale. He was hooked. I’d seen enough.

I walked back to my place and called the precinct station, but they didn’t have anything on anyone matching Mrs. Doe’s description. I was stymied. I played a couple hands of solitaire and lost, so I drank myself to sleep.

The phone rang early the next morning. I was still trying to remember why the Munchkins had tied me down and let Sydney Greenstreet walk all over my forehead when I picked up the receiver and said, “Talk fast.”

“This is Lt. Orkin, Twelfth Precinct. I hear you were looking for someone yesterday. Green skin, antennae, eyes like silver dollars?”

“That’s right.”

“She’s in the morgue. A couple of sailors found her about an hour ago in back of a tattoo parlor. Maybe the tattoo artist got drunk and set his needle on automatic.”

“Very funny, lieutenant. How’d it happen?”

“Can’t say. Third degree burns all over the body. Got any ideas?”

“Must’ve been playing with matches,” I replied, and hung up.

I sobered up fast and took a taxi back to the nightclub. It was easy to find the girl — I just followed the scent of cheap perfume and expensive lingerie.

“What’s your name, baby?”

“Candy. What’s yours?”

I flashed my badge. “Maurice Hohenzollern, private detective.”

“What’s this all about?” she sniveled.

I pushed her against the wall. “It’s about knives, stiffs, cold marble and cold blood. It’s about a quick trip to the next world. It’s about murder, honey.”

“You mean…”

“Yes. Your boyfriend finally found his wife, without my help. Tough luck for her — she’s cooling her green heels in the morgue right now. You’d better talk.” She fell into my arms like a rag doll, sobbing.

“He came here about a week ago. He seemed so nice, so polite. Of course he fell in love with me right away. And then…he started talking about home, about all those long hot years living by a canal in the middle of a desert, with only his wife for company. It must have been horrible.”

“A desert?” I asked. “Where?”

“Don’t you understand?” she cried. “On Mars.” She broke down.

“It’s okay, sweetheart,” I said, giving her a brotherly hug. I made a mental note to look her up next time I was in the area. So that was it: Martians. Everything began to fall into place. It explained the accent and the “I Like Ike” button, to start with.

Suddenly I felt a pressure in the small of my back. I turned around and found myself staring down the nozzle of a mean little ray gun held by a knobby green hand.

“So now you know,” he hissed. “But before I fry your brain I may as well tell you the rest. My name is not John Doe, it is Xanthu. Yes, I come from Mars. It is a dying planet. You would believe me if you had met my wife. I lived with her for 3,000 years, raising sand worms for export. When I finally built a ship to escape to Earth, she made me take her too. After we landed, I managed to lose her, but then I decided I must kill her instead. I hired you to give myself an alibi. When I finally caught her it took hours for her to die, even with my gun at its highest setting. Eventually her brain melted. Now I will kill you as well, and then I can live with Candy in peace forever.”

“But she’s going to join the Marines,” I said. It was sheer inspiration. He nearly dropped his gun. I took the opportunity to give him an elbow in the throat, a trick I learned in the Pioneer Girls that has never failed me yet. He crumpled to the ground like last week’s flowers.

It was hard to explain things to the police. I ended up telling them he was a shoe salesman from New Jersey, since nothing else seemed possible. When I got home, I opened my top drawer and took out the bottle of rye. Now it looked about half full.