«Not a specific suspect, no. But we've eliminated a lot of possibles.»

«You haven't got a fucking clue, have you? Jesus, she's murdered in full view, and you don't have one single idea who did it. What kind of policeman are you?»

I steeled my expression, and said: «A persistent one. I'll find the culprit eventually, but I'll do it a lot quicker with your cooperation.»

He wilted under the rebuke, just as I expected. Davis was a grieving drunk prone to tantrums, not an anti-establishment rebel.

«I want to know about her,» I said more gently. «Did she talk to you about her work?»

«Some. We were a stimulus to each other. I listened to her describe her genetics projects; and I explained my own field to her. She was interesting and interested. That's why our relationship worked so well, we were compatible right across the board.»

«You're an astronomer?»

«Astrophysicist.» He grinned savagely. «Get it right. There's some in my profession who'd be badly offended by that. Think yourself lucky I'm so easygoing.»

«Does the JSKP pay for your work?»

«Some of it, my position is part-funded by the University of Paris. I'm supposed to be studying Jupiter's gravitational collapse. Interesting field.»

«You don't sound very enthusiastic.»

«Oh, there's enough to captivate me. But there's a lot else going on up here, more provoking puzzles. Even after all this time observing Jupiter at close range, and dropping robot probes into the atmosphere, there's very little we know about it, certainly what goes on within the deeper levels, below the altitude which the probes can reach. Our solid-state sensor drones implode long before they reach the semisolid layers. All we've got on the interior is pure speculation, we don't understand what happens to matter at those sort of compression factors, not for sure. And Christ alone knows what's actually taking place at the core. There's a hundred theories.»

«And Penny was interested?»

He picked the glass of vodka up, swirled the ice, then put it down without drinking any. «Yeah. Academically, anyway. She could follow the arguments.»

«What did she tell you about her work?»

«Whatever she wanted. What bugged her, what was going well, new ideas. Christ, she would come up with some bizarre concepts at times. Balloon fish that could live in Jupiter's atmosphere, mythological creatures, webs of organic conductors which could fly in the Earth's ionosphere.»

«Anything really radical?»

«What? Those not enough for you? Don't you want to see dragons perching on the mountaintops again?»

«I meant something which could upset national economies, or put companies out of business.»

«No, nothing like that. Penny wasn't an anarchist. Besides, ninety per cent of her time was still tied up with developing the next generation of habitats. She was determined to do as much as she could before . . .» He trailed off helplessly.

«So, no secret projects, no fundamental breakthrough to crown her achievements?»

«No. The habitats were enough for her.»

«Did she ever mention anyone she was having trouble with?»