We were down.  We'd landed on Altair-4.

We were ready for anything - but it didn't seem to be happening.

Like some huge impossible mushroom growth, the ship squatted on her landing gear.  With the turquoise-tinted light gleaming on her hull, she seemed to loom even bigger and sleeker than she had on the day, ten Earth-years and countless millions of miles ago, when I'd caught my first sight of her at the launching base.

Inside her, men were stationed at her blast and disintegrator guns, the open gun-ports making black holes in her glittering flanks.  Outside, the rest of the hands, all armed, were spread in a protective circle.  Some little way beyond the circle were the Officers - and, much to my delighted surprise, I was with them.  I'd been afraid that, as we were still on Alert-A and ready for trouble, I was going to be ordered to stay aboard, in the Surgery.  But I hadn't been, thank God.

And - thank God again - no one was interfering with me.  Adams, binoculars at his eyes, was making a slow and careful survey of the horizon.  Farman was pacing up and down, dragging at a cigarette.  Quinn, on hands and knees, seemed lost in examination of the sandy soil.  I was on my own - and very lucky.  The others had to think, but I didn't.  I could let them do the worrying and give myself up to my senses and try to absorb the strangeness...

It took some absorbing.  Gone entirely was the feeling of similarity to Earth.  We were on a desert, with a sun beating down on us.  There was air we could breathe and sand we could walk on.  There were vistas our eyes could see, and we could hear the crunching of our boots as we moved.  But nothing was the same; nothing was even remotely Earthlike...

But I felt - wonderful.  I drew in deep breaths of the soft, heady air.  I looked up at the turquoise sky, and down at the red sand.  I looked around at the weird stalagmitic spears of blue-grey rock which thrust up through the sand in haphazard clusters, and then I looked past them and out around the horizon at the ranges of jagged green-grey mountains on one side and the gentler slopes on the other; slopes which, shimmering in the glare, might be clothed in vegetation...

I was startled by Quinn's voice from close beside me.  It said, "Look at this, Doctor," and I turned to see him holding out to me a chunk of the blue-grey rock.

"An extraordinary formation," he said.  "Harder than granite, but lighter than pumice!"

I stretched out my hand for the thing - but never finished the gesture.  Because from behind me came a shout in Adams' voice:

"Bosun!  Alert - your left front!"

I whipped around and saw that Adams was pointing out across the red desert.  Miles away in the middle distance, a dark cloud of sand was whirling toward us at tremendous speed.  I told myself it might be some trick of wind, like a 'dust-devil' in Arizona, but somehow I knew it wasn't.

I heard the Bosun barking orders - and saw four of the crewmen move up to stand level with Adams.  After that, none of us moved.  Or spoke.

The sand-cloud whirled on, making straight for us - and I saw, inside or perhaps just ahead of it, something from which the light struck metallic gleams.