Never buy anything at a secondhand organ bank. And while I'm handing out good advice, don't outfit yourself for a trip to Venus until you get to Venus.

I wish I had waited. But while shopping around at Coprates a few weeks before my vacation, I happened on this little shop and was talked into an infraeye at a very good price. What I should have asked myself was what was an infraeye doing on Mars in the first place?

Think about it. No one wears them on Mars. If you want to see at night, it's much cheaper to buy a snooperscope. That way you can take the damn thing off when the sun comes up. So this eye must have come back with a tourist from Venus. And there's no telling how long it sat there in the vat until this sweet-talking old guy gave me his line about how it belonged to a nice little old schoolteacher who never... ah, well. You've probably heard it before.

If only the damn thing had gone on the blink before I left Venusburg. You know Venusburg: town of steamy swamps and sleazy hotels where you can get mugged as you walk down the public streets, lose a fortune at the gaming tables, buy any pleasure in the known universe, hunt the prehistoric monsters that wallow in the fetid marshes that are . just a swampbuggy ride out of town. You do? Then you should know that after hours -when they turn all the holos off and the place reverts to an ordinary cluster of silvery domes sitting in darkness and eight hundred degree temperature and pressure enough to give you a sinus headache just thinking about it, when they shut off all the tourist razzle-dazzle -it's no trouble to find your way to one of the rental agencies around the spaceport and get medicanical work done. They'll accept Martian money. Your Solar Express Card is honored. Just walk right in, no waiting.

However...

I had caught the daily blimp out of Venusburg just hours after I touched down, happy as a clam, my infraeye working beautifully. By the time I landed in Cui-Cui Town, I was having my first inklings of trouble. Barely enough to notice; just the faintest hazing in the right-side peripheral vision. I shrugged it off. I had only three hours in Cui-Cui before the blimp left for Last Chance. I wanted to look around. I had no intention of wasting my few hours in a body shop getting my eye fixed. If it was still acting up at Last Chance, then I'd see about it.

Cui-Cui was more to my liking than Venusburg. There was not such a cast-of-thousands feeling there. On the streets of Venusburg the chances are about ten to one against meeting a real human being; everyone else is a holo put there to spice up the image and help the streets look not quite so empty. I quickly tired of toot-suited pimps that I could see right through trying to sell me boys and girls of all ages. What's the point? Just try to touch one of those beautiful people.

In Cui-Cui the ratio was closer to fifty-fifty. And the theme was not decadent corruption, but struggling frontier. The streets were very convincing mud, and the wooden storefronts were tastefully done. I didn't care for the eight-legged dragons with eyestalks that constantly lumbered through the place, but I understand they are a memorial to the fellow who named the town That's all right, but I doubt if he would have liked to have one of the damn things walk through him like a twelve-ton tank made of pixie dust.

I barely had time to get my feet "wet" in the "puddles" before the blimp was ready to go again. And the eye trouble had cleared up. So I was off to Last Chance.

I should have taken a cue from the name of the town. And I had every opportunity to do so. While there, I made my last purchase of supplies for the bush. I was going out where there were no air stations on every corner, and so I decided I could use a tagalong.

Maybe you've never seen one. They're modern science's answer to the backpack. Or maybe to the mule train, though in operation you're sure to be reminded of the safari bearers in old movies, trudging stolidly along behind the White Hunter with bales of supplies on their heads. The thing is a pair of metal legs exactly as long as your legs, with equipment on the top and an umbilical cord attaching the contraption to your lower spine. What it does is provide you with the capability of living on the surface for four weeks instead of the five days you get from your Venus-lung The medico who sold me mine had me laying right there on his table with my back laid open so he could install the tubes that carry air from the tanks in the tagalong into my Venus-lung. It was a golden opportunity to ask him to check the eye. He probably would have, because while he was hooking me up he inspected and tested my lung and charged me nothing. He wanted to know where I bought it, and I told him Mars. He clucked, and said it seemed all right: He warned me not to ever let the level of oxygen in the lung get too low, to always charge it up before I left a pressure dome, even if I was only going out for a few minutes. I assured him that I knew all that and would be careful. So he connected the nerves into a metal socket in the small of my back and plugged the tagalong into it. He tested it several ways and said the job was done.

And I didn't ask him to look at the eye. I just wasn't thinking about the eye then. I'd not even gone out on the surface yet. So I'd no real occasion to see it in action. Oh, things looked a little different, even in visible light. There were different colors and very few shadows, and the image I got out of the infraeye was fuzzier than the one from the other eye. I could close one eye, then the other, and see a real difference. But I wasn't thinking about it.

So I boarded the blimp the next day for the weekly scheduled flight to Lodestone, a company mining town close to the Fahrenheit Desert. Though how they were able to distinguish a desert from anything else on Venus was still a mystery to me. I was enraged to find that, though the blimp left half-loaded, I had to pay two fares: one for me, and one for my tagalong. I thought briefly of carrying the damn thing in my lap but gave it up after a ten-minute experiment in the depot. It was full of sharp edges and poking angles, and the trip was going to be a long one. So I paid. But the extra expense had knocked a large hole in my budget.

From Cui-Cui the steps got closer together and harder to reach. CuiCui is two thousand kilometers from Venusburg, and it's another thousand to Lodestone. After that the passenger service is spotty. I did find out how Venusians defined a desert, though. A desert is a place not yet inhabited by human beings. So long as I was still able to board a scheduled blimp, I wasn't there yet.

The blimps played out on me in a little place called Prosperity. Population seventy-five humans and one otter. I thought the otter was a holo playing in the pool in the town square. The place didn't look prosperous enough to afford a real pool like that with real water. But it was. It was a transient town catering to prospectors. I understand that a town like that can vanish overnight if the prospectors move on. The owners of the shops just pack up and haul the whole thing away. The ratio of the things you see in a frontier town to what really is there is something like a hundred to one.

I learned with considerable relief that the only blimps I could catch out of Prosperity were headed in the direction I had come from. There was nothing at all going the other way. I was happy to hear that and felt it was only a matter of chartering a ride into the desert. Then my eye faded out entirely.

I remember feeling annoyed; no, more than annoyed. I was really angry. But I was still viewing it as a nuisance rather than a disaster. It was going to be a matter of some lost time and some wasted money.