'Lutchman has a fever next morning: 99.8 at 8 a.m. ("Looking ill", Ronnie notes). Looks like it's time for Doc Manson to jump out of his bathtub; maybe malaria really is spread through mosquito-dust. Ronnie gets ready to pop the corks; he's about to call his agent. But then comes the letdown. Young Lutchman doesn't just look healthy; he is healthy. He's allergic to mosquito-dust, is all. A day later he's so fit he could run the Begumpett marathon: no sign of malaria in his blood. That's the end of the line for the mosquito-dust theory. Ronnie's free to go back to Abdul Kadir again: he's been headed off at the pass.'

'Wait, wait,' Antar broke in. 'I want to be clear about this. Are you arguing that Lutchman was sent to Ross's lab specifically in order to disprove Manson's theory?'

'I'm not arguing anything,' said Murugan. 'Just taking the facts as they come. And the facts are these: Ronnie's been working on the malaria bug for about a month when Abdul Kadir and Lutchman walk into his life. Ronnie hasn't made a secret of what he's doing: he's put the word out about needing malaria patients. If someone was watching let's just say if - if someone was watching, if someone was looking for a research scientist to do certain kinds of experiments, then this is when they would have picked up the buzz. So this someone, who's watching carefully, maybe reading Ronnie's lab notes and his letters to Doc Manson, this someone decides, OK, it's time to get a new player in place. The first thing they've got to do is to make sure Ronnie doesn't get any patients. So they spread the word about witchcraft; it flies through the bazaar; Ronnie becomes the bogeyman of Begumpett.

'By mid-May they know Ronnie's getting desperate, no patients, no parasites, no nothing. He can't get anyone to come to his parties and he can't figure out why. This is when they send him Abdul Kadir who's got industrial-size parasites; they hold Ronnie's hand as he puts his first twos and twos together; they're happy, everything's on schedule, they're leading Ronnie exactly where they want him to go. And then Ronnie gets his letter from boss-man Manson; suddenly everything flies off track. Ronnie goes off into left field, with this mosquito-powder stuff. They go wild: they know there's nothing at the end of that trail; they have to find a way to turn him back in the right direction. So what do they do? They send him Lutchman.'

'But why Lutchman?' said Antar.

'Let me put it like this,' said Murugan, 'whoever picked Lutchman knew exactly what they were doing. For one thing, they knew enough about microscopy to make sure that he didn't have any malaria parasites in his blood. Ronnie was being second guessed here. Somebody had figured out what was going to happen if Ronnie got a positive result after feeding Lutchman mosquito water. He was going to link the parasites to Doc Manson's theory and bingo! there goes the schedule. Months, maybe years could go by while Ronnie chases around Begumpett, making the 19th Madras Infantry drink dead mosquitoes.

'So they stepped in; they sent him someone who didn't have any parasites. Remember that this is a place where the rates of malaria in the general population are so high they're off the charts. It isn't easy to find people who don't have any trace of the parasite in their blood. But these guys reach into their bag, pick out someone who's just right, and then they send him over to Begumpett General. It works: Ronnie's back on track, and right on schedule. And better still they've planted Lutchman exactly where they want him, where he can run interference for the whole team.'

'But,' said Antar, 'wouldn't Ross have noticed something so obvious?'

'Ronnie?' Murugan laughed. 'Ronnie wouldn't have noticed if Lutchman wore it on a T-shirt. If anything but a parasite comes calling, Ronnie's out to lunch. The way Ronnie tells it, he was short of help at the time, so he decided to hire Lutchman as a houseboy-cum-gofer. All that Ron ever knew about him was that his name was "Lutchman" and that he was a "dhooley-bearer" by trade.

'For the next thirty-four months – the entire period that Ron's working on malaria – Lutchman sticks to him like roll-on deodorant. Starting May 1895, until July 1898, when Ron makes his final breakthrough in Calcutta, Lutchman almost never lets Ron out of his sight. He gets pretty good at doing luggage impersonations. "I left Secunderabad with the smallest possible 'kit'," says Ronnie, "my microscope and my faithful Lutchman."

'It gets so that even Ron can't help noticing that Lutchman's making some pretty important connections for him. In April 1897, Ron takes a break in the Nilgiri Hills. He takes Lutchman with him, to Ootacamund – "a bit of England placed on the rounded tops of the Nilgiri Hills", says Ron. But Ron goes down to the Westbury coffee estate in a valley, looking for malaria parasites, and there for the first time in his life, he gets malaria.

'While he's recouping Lutchman succeeds in planting a crucially important idea in his head: that the malaria vector might be one particular species of mosquito. "Oh, yeah?" says Ron; he thinks Lutchman's full of shit: he's been getting a lot of negative results but it's never occurred to him that they might have something to do with family differences among mosquitoes.

"Tell you what, Lutch," says Ron, "next time I want your help I'll ask for it." But after Lutchman plants this little seed something begins to stir in the mud; a creature begins to take shape in Ron's head.

'He starts eyeballing every different species of mosquito he can get his hands on. Trouble is Ron doesn't know a goddam thing about mosquitoes: he's never even heard the word anopheles. He ends up chasing after Culex, Stegomyia - going every which way but ahead. Now Lutchman cuts in once again. On August 15 1897 he goes into a huddle with the rest of his crew and decides something's got to be done double quick.

'The way Ronnie tells it: "Next morning, 16 August, when I went again to hospital after breakfast, the Hospital Attendant (I regret I have forgotten his name) pointed out a small mosquito seated on the wall with its tail sticking outwards." Ronnie kills it with a puff of tobacco smoke and cuts it open: nothing. But at last he's on the right track: Lutchman's got him chasing after the real malaria vector. Ron still doesn't know they're called anopheles: names them "dappled-wing mosquitoes".

'Next day Lutchman makes sure Ronnie gets more of the same: sends him a jarful of anopheles with the same attendant. "Sure enough," says Ronnie, "there they were: about a dozen big, brown fellows, with fine tapered bodies and spotted wings, hungrily trying to escape through the gauze covering of the flask which the Angel of Fate had given to my humble retainer! – dappled-winged mosquitoes'… " Angel of Fate my ass! With Ronnie it always has to be some Fat Cat way up in the sky: what's under his nose he can't see.

'On August 20 1897 Ronnie makes his first major breakthrough: he sees the placement of Plasmodium zygotes in the stomach sac of Anopheles stephensii. "Eureka," he says to his diary, "the problem is solved."

"Whew!" says Lutchman, skimming the sweat off his face. "Thought he'd never get it."

'Later Ron asks him: "Yo, Lutch, where'd you get that hot tip about mosquito species?" Lutchman plays dumb: "Oh, some villagers up in them hills happened to mention it one morning while grazing their goats." And you know what? Ron buys it. He thinks Lutchman hit upon this bright idea while gambolling in the hills with happy natives.

'What gets me about this scenario is the joke. Here's Ronnie, right? He thinks he's doing experiments on the malaria parasite. And all the time it's him who is the experiment on the malaria parasite. But Ronnie never gets it; not to the end of his life.'