'Distilled water,' he said. 'Got to protect the sinuses.'

And he tipped Halleck a wink.

He's probably treated babies for pneumonia with that shit running around in his head, Halleck thought, but the thought had no real power. Right now he couldn't help liking Houston a little, because Houston had given him good news. Right now all he wanted in the world was to sit here with his hands laced across his diminished belly and explore the depth of his shaky relief, to try it out like a new bicycle, or test-drive it like a new car. It occurred to him that when he walked out of Houston's office he was probably going to feel almost newborn. A director filming the scene might well want to put Thus Spake Zarathustra on the soundtrack. This thought made Halleck first grin, hen laugh aloud.

'Share the funny,' Houston said. 'In this sad world we need all the funnies we can get, Billy-boy.' He sniffed loudly and then lubricated his nostrils with a fresh Q-tip.

'Nothing,' Halleck said. 'It's just … I was scared, you know. I was already dealing with the big C. Trying to.'

'Well, you may have to, 'Houston said, 'but not this year. I don't need to see the lab results on the Hayman-Reichling cards to tell you that. Cancer's got a look. At least when it's already gobbled up thirty pounds, it does.'

'But I've been eating as much as ever. I told Heidi I'd been exercising more, and I have, a little, but she said you couldn't lose thirty pounds just by beefing up your exercise regimen. She said you'd just make hard fat.'

'That's not true at all. The most recent tests have showed exercise is much more important than diet. But for a guy who is -who was – as overweight as you were, she's got a point. You take a fatty who radically increases his level of exercise, and what the guy usually gets is the booby prize – a good solid class-two thrombosis. Not enough to kill you, just enough to make sure you're never going to walk around all eighteen holes again or ride the big roller coaster at Seven Flags Over Georgia.'

Billy thought the cocaine was making Houston talkative.

'You don't understand it,' he said. 'I don't understand it, either. But in this business I see a lot of things I don't understand. A friend of mine who's a neurosurgeon in the city called me in to look at some extraordinary cranial X rays about three years ago. A male student at George Washington University came in to see him because he was having blinding headaches. They sounded like typical migraines to my colleague – the kid fit the personality type to a tee – but you don't want to screw around with that sort of thing because headaches like that are symptomatic of cranial brain tumors even if the patient isn't having phantom olfactory referents -smells like shit, or rotten fruit, or old popcorn, or whatever. So my buddy took a full X-ray series, gave the kid an EEG, sent him to the hospital to have a cerebral axial tomography. Know what they found out?'

Halleck shook his head.

'They found out that the kid, who had stood third in his high-school class and who had been on the dean's list every semester at George Washington University, had almost no brain at all. There was a single twist of cortical tissue running up through the center of his skull – on the X rays my colleague showed me, it looked for all the world like a macrame drape-pull – and that was all. That drape-pull was probably running all of his involuntary functions, everything from breathing and heart rate to orgasm. Just that one rope of brain tissue. The rest of the kid's head was filled with nothing but cerebrospinal fluid. In some way we don't understand, that fluid was doing his thinking. Anyway, he's still excelling in school, still having migraines, and still fitting the migraine personality type. If he doesn't have a heart attack in his twenties or thirties that kills him, they'll start to taper off in his forties.'

Houston pulled the drawer open, took out the cocaine, and took some. He offered it to Halleck. Halleck shook his head.

'Then,' Houston resumed, 'about five years ago I had an old lady come into the office with a lot of pain in her gums. She's died since. If I mentioned the old bitch's name, you'd know it. I took a look in there and Christ Almighty, I couldn't believe it. She'd lost the last of her adult teeth almost ten years before – I mean, this babe was pushing ninety – and here was a bunch of new ones coming up … five of them in all. No wonder she was having gum pain, Billy! She was growing a third set of teeth. She was teething at eighty-eight years of age.'

'What did you do?' Halleck asked. He was hearing all of this with only a very limited part of his mind – it flowed over him, soothing, like white noise, like Muzak floating down from the ceiling in a discount department store. Most of his mind was still dealing with relief – surely Houston's cocaine must be a poor drug indeed compared to the relief he was feeling. Halleck thought briefly of the old Gypsy with the rotten nose, but the image had lost its darkish, oblique power.

'What did I do?' Houston was asking. 'Christ, what could I do? I wrote her a prescription for a drug that's really nothing more than a high-powered form of Num-Zit, that stuff you put on a baby's gums when it starts to teethe. Before she died, she got three more in – two molars and a canine.

'I've seen other stuff, too, a lot of it. Every doctor sees weird shit he can't explain. But enough of Ripley's Believe It Or Not. The fact is, we don't understand very goddamn much about the human metabolism. There are guys like Duncan Hopley … You know Dunc?'

Halleck nodded. Fairview's chief of police, rouster of Gypsies, who looked like a bush-league Clint Eastwood.

'He eats like every meal was his last one,' Houston said. 'Holy Moses, I never seen such a bear for chow. But his weight sticks right around one-seventy, and because he's six feet tall, that makes him just about right. He's got a souped-up metabolism; he's burning the calories off at twice the pace of, let's say, Yard Stevens.'

Halleck nodded. Yard Stevens owned and operated Heads Up, Fairview's only barber shop. He went maybe three hundred pounds. You looked at him and wondered if his wife tied his shoelaces.

'Yard is roughly the same height as Duncan Hopley,' Houston said, 'but the times I've seen him at lunch, he's just picking at his food. Maybe he's a big closet eater. Could be. But I'd guess not. He's got a hungry face, you know what I mean?'

Billy smiled a little and nodded. He knew. Yard Stevens looked, in his mother's phrase, 'like his food wasn't doing him any good.'

'I'll tell you something else, too – although I s'pose it's tales out of school. Both of those men smoke. Yard Stevens claims a pack of Marlboro Lights a day, which means he probably smokes a pack and a half, maybe two. Duncan claims he smokes two packs of Camels a day, which could mean he's doing three, three and a half. I mean, did you ever see Duncan Hopley without a cigarette in his mouth or in his hand?'

Billy thought about it and shook his head. Meanwhile; Houston had helped himself to another blast. 'Gah, that's enough of that,' he said, and slammed the drawer shut with authority.

'Anyway, there's Yard doing a pack and a half of low-tar cigarettes a day, and there's Duncan doing three packs of black lungers every day – maybe more. But the one who's really inviting lung cancer to come in and eat him up is Yard Stevens. Why? Because his metabolism sucks, and metabolic rate is somehow linked to cancer.

'You have doctors who claim that we can cure cancer when we crack the genetic code. Some kinds of cancer, maybe. But it's never going to be cured completely until we understand metabolism. Which brings us back to Billy Halleck, the Incredible Shrinking Man. Or maybe the Incredible Mass-Reducing Man would be better. Not Mass-Producing; Mass-Reducing.' Houston laughed a strange and rather stupid whinnying laugh, and Billy thought: If that's what coke does to you, maybe I'll stick to Ring-Dings.