Perhaps it's a phototrope, its biological cycle triggered by the sunlight that filters down through the ice. Or it could have been attracted like a moth to a candle. Our floodlights must have been more brilliant than anything that Europa has ever known, even the Sun itself...

Then the ship crashed. I saw the hull split, a cloud of snowflakes form as moisture condensed. All the lights went out, except for one, swinging back and forth on a cable a couple of metres above the ground.

I don't know what happened immediately after that. The next thing I remember, I was standing under the light, beside the wreck of the ship, with a fine powdering of fresh snow all around me. I could see my footsteps in it very clearly. I must have run there; perhaps only a minute or two had elapsed...

The plant – I still thought of it as a plant – was motionless. I wondered if it had been damaged by the impact; large sections – as thick as a man's arms – had splintered off, like broken twigs.

Then the main trunk started to move again. It pulled away from the hull, and began to crawl towards me. That was when I knew for certain that the thing was light-sensitive: I was standing immediately under the thousand-watt lamp, which had stopped swinging now.

Imagine an oak tree – better still, a banyan with its multiple trunks and roots – flattened out by gravity and trying to creep along the ground. It got to within five metres of the light, then started to spread out until it had made a perfect circle around me. Presumably that was the limit of its tolerance – the point at which photo-attraction turned to repulsion.

After that, nothing happened for several minutes, I wondered if it was dead – frozen solid at last.

Then I saw that large buds were forming on many of the branches. It was like watching a time-lapse film of flowers opening. In fact I thought they were flowers – each about as big as a man's head.

Delicate, beautifully coloured membranes started to unfold. Even then, it occurred to me that no one – no thing – could ever have seen these colours properly, until we brought our lights – our fatal lights – to this world.

Tendrils, stamens, waving feebly... I walked over to the living wall that surrounded me, so that I could see exactly what was happening. Neither then, or at any other time, had I felt the slightest fear of the creature. I was certain that it was not malevolent – if indeed it was conscious at all.

There were scores of the big flowers, in various stages of unfolding. Now they reminded me of butterflies, just emerging from the chrysalis – wings crumpled, still feeble – I was getting closer and closer to the truth.

But they were freezing – dying as quickly as they formed. Then, one after another, they dropped off from the parent buds. For a few moments they flopped around like fish stranded on dry land – and at last I realized exactly what they were. Those membranes weren't petals – they were fins, or their equivalent. This was the free-swimming larval stage of the creature. Probably it spends much of its life rooted on the sea-bed, then sends these mobile offspring in search of new territory. Just like the corals of Earth's oceans.

I knelt down to get a closer look at one of the little creatures. The beautiful colours were fading now, to a drab brown. Some of the petal-fins had snapped off, becoming brittle shards as they froze. But it was still moving feebly, and as I approached it tried to avoid me. I wondered how it sensed my presence.

Then I noticed that the stamens – as I'd called them -all carried bright blue dots at their tips. They looked like tiny star sapphires – or the blue eyes along the mantle of a scallop – aware of light, but unable to form true images. As I watched, the vivid blue faded, the gems became dull, ordinary stones...

Dr Floyd – or anyone else who is listening – I haven't much more time; my life-support system alarm has just sounded. But I've almost finished.

I knew then what I had to do. The cable to that thousand-watt lamp was hanging almost to the ground. I gave it a few tugs, and the light went out in a shower of sparks.

I wondered whether it was too late. For a few minutes nothing happened. So I walked over to the wall of tangled branches around me – and kicked it.

Slowly, the creature started to unweave itself, and to retreat back to the Canal. I followed it all the way back to the water, encouraging it with more kicks when it slowed down, feeling the fragments of ice crunching all the time beneath my boots... As it neared the Canal, it seemed to gain strength and energy, as if it knew it was approaching its natural home. I wondered if it would survive, to bud again.

It disappeared through the surface, leaving a few last dead larvae on the alien land. The exposed free water bubbled for a few minutes until a scab of protective ice sealed it from the vacuum above. Then I walked back to the ship to see if there was anything to salvage – I don't want to talk about that.

I've only two requests to make, Doctor. When the taxonomists classify this creature , I hope they'll name it after me.

And – when the next ship comes home – ask them to take our bones back to China.

I'll lose power in a few minutes – wish I knew whether anyone was receiving me. Anyway, I'll repeat this message as long as I can...

This is Professor Chang on Europa, reporting the destruction of the spaceship Tsien. We landed beside the Grand Canal and set up our pumps at the edge of the ice -

MISS PRINGLE RECORD

Here comes the Sun! Strange – how quickly it seems to rise, on this slowly turning world! Of course, of course – the disc's so small that the whole of it pops above the horizon in no time... Not that it makes much difference to the light – if you weren't looking in that direction, you'd never notice that there was another sun in the sky.

But I hope the Europs have noticed. Usually it takes them less than five minutes to start coming ashore after the Little Dawn. Wonder if they already know I'm here, and are scared...

No – could be the other way round. Perhaps they're inquisitive – even anxious to see what strange visitor has come to Tsienville... I rather hope so...

Here they come! Hope your spysats are watching – Falcon's cameras recording...

How slowly they move! I'm afraid it's going to be very boring trying to communicate with them... even if they want to talk to me...

Rather like the thing that overturned Tsien, but much smaller... They remind me of little trees, walking on half a dozen slender trunks. And with hundreds of branches, dividing into twigs, which divide again... and again. Just like many of our general-purpose robots... what a long time it took us to realize that imitation humanoids were ridiculously clumsy, and the proper way to go was with myriad of small manipulators! Whenever we invent something clever, we find that Mother Nature's already thought of it...

Aren't the little ones cute – like tiny bushes on the move. Wonder how they reproduce – budding? I hadn't realized how beautiful they are. Almost as colourful as coral reef fish – maybe for the same reasons... to attract mates, or fool predators by pretending to be something else...

Did I say they looked like bushes? Make that rose-bushes – they've actually got thorns! Must have a good reason for them...

I'm disappointed. They don't seem to have noticed me. They'll all heading into town, as if a visiting spacecraft was an everyday occurrence... only a few left... maybe this will work...

I suppose they can detect sound vibrations – most marine creatures can – though this atmosphere may be too thin to carry my voice very far...

FALCON – EXTERNAL SPEAKER...

HELLO, CAN YOU HEAR ME? MY NAME IS FRANK POOLE... AHEM... I COME IN PEACE FOR ALL MANKIND...