Looking up at the ice ceiling above me, I saw how it had been shaped and scraped, as if by lobster claws. ‘So the spiders keep these chambers open, to allow the methane-creating reactions to continue. And the tube-fish carry the methane to the ocean, through vents they in turn help keep open.’
‘That’s it,’ Michael Poole said, wonder in his voice. ‘They do it to keep a supply of methane pumping up into the atmosphere. And they’ve been doing it for billions of years. Have to have been, for the ecologies up there to have evolved as they have – the tube-fish, the CHON sponges, the silanes. This whole world is an engine, a very old engine. It’s an engine for creating methane, for turning what would otherwise be just another nondescript ice moon into a haven, whose purpose is to foster the life forms that inhabit it.’
‘Ha!’ I barked laughter. ‘So all this is technology. Therefore the spiders are clearly sentient – or their makers are, or were. You don’t even need this hatch in the ground to make that case. You have found precisely what you were afraid of, haven’t you, Michael Poole? Sentience at the heart of Titan. You will never be allowed to open it up for exploitation now. So much for your commercial ambitions!’
-Xeelee: Endurance, "Return to Titan"