Dr Kim brought the screen to life once more. It showed plain text: ALL THESE WORLDS ARE YOURS EXCEPT EUROPA. ATTEMPT NO LANDINGS THERE. The same message was repeated about a hundred times, then the letters became garbled.

'And we never have tried to land there?' asked Poole.

'Only once, by accident, thirty-six years later – when the USSS Galaxy was hijacked and forced down there, and her sister ship Universe had to go to the rescue. It's all here -with what little our robot monitors have told us about the Europans.'

'I'm anxious to see them.'

'They're amphibious, and come in all shapes and sizes. As soon as Lucifer started melting the ice that covered theirt whole world, they began to emerge from the sea. Since then, they've developed at a speed that seems biologically impossible.'

'From what I remember about Europa, weren't there lots of cracks in the ice? Perhaps they'd already started crawling through and having a look round.'

'That's a widely accepted theory. But there's another, much more speculative, one. The Monolith may have been involved, in ways we don't yet understand. What triggered that line of thought was the discovery of TMA ZERO, right here on Earth, almost five hundred years after your time. I suppose you've been told about that?'

'Only vaguely – there's been so much to catch up with! I did think the name was ridiculous – since it wasn't a magnetic anomaly – and it was in Africa, not Tycho!'

'You're quite right, of course, but we're stuck with the name. And the more we learn about the Monoliths, the more the puzzle deepens. Especially as they're still the only real evidence for advanced technology beyond the Earth.'

'That's surprised me. I should have thought that by this lime we'd have picked up radio signals from somewhere. The astronomers started searching when I was a boy!'