Matty laughed. 'I said I was his son, and that my mam wanted to find out if he had any money coming from an employer. Apparently he's owed some back wages, but his landlord's already got his eye on that for rent.'

'Where was the company based?' Sherlock called back.

'They've got a main office near the market, but they've also got a warehouse on the edge of town where the cove worked. That's probably the one you burned down!'

Sherlock reflected, as the narrowboat drifted on, pulled by Matty's horse. The man who died had been a tailor, making uniforms. The warehouse where he had worked had been full of boxes, which the thugs had loaded on to a cart. Boxes of uniforms? It seemed likely. But that still didn't explain why the man had died, or how, and it didn't explain the death of the second man, the one in the woods.

The sky to the East was the deep purple of a fresh bruise, and the trees lining the river were just visible as darker shapes against adark background. A lone star shone brightly, close to the horizon. Ahead, Sherlock could see a black arch crossing their path: probably a bridge. Perhaps even the one that he and Matty had sat on, only a day or two before, watching the fish in the river.

Albert snickered, as if something had startled him. Sherlock stared at the bank, trying to make out the animal's shape against the darkness of the hedges that lined the bank. The sound of its hoofs against the path changed. To Sherlock it sounded as if the horse was trying to move away from something that was getting too close.

Matty said something calming more a rea.s.suring noise than actual words but Sherlock could tell from the tone of his voice that he was concerned. What was the problem? Was there a wild dog wandering around, spooking the horse, or had it just smelt something unexpected?

Sherlock was about to call to Matty and ask him what the problem was when something moved on the bridge beyond the black shape of Matty's head and shoulders.

Sherlock switched his gaze on to the dark shape that was crossing the river ahead of them. Something was breaking the smooth arc of the bridge: a lumpy shadow slightly off-centre. Two Two lumpy shadows, as the first one was joined by a second. They conferred for a few moments, leaning together, and then moved apart. lumpy shadows, as the first one was joined by a second. They conferred for a few moments, leaning together, and then moved apart.

Locals from Farnham, out and about early? Poachers, perhaps?

Theories that Sherlock abandoned when the flare of a match momentarily illuminated a swarthy face that he recognized from the warehouse.

The thug named Clem.

The flame turned into a warm glow that spilt across the brickwork. Clem held a lamp high, casting its light down on to the approaching narrowboat. As they headed towards the bridge Sherlock could see a cruel smile twisting his mouth. The glow from the lamp outlined Matty's figure as he stood up in the bows of the boat. He seemed as if he was about to say something, but Clem swung the lamp above his head, sending shadows flickering everywhere, and then threw the lamp at Matty's head.

Matty ducked, and the lamp bounced twice before shattering across the back of the narrowboat, spilling burning oil everywhere. Tiny slivers of flame caught hold of the wood, licking hungrily across the veneer. Sherlock glanced around. They were on a river, for heaven's sake, and he could see no way of getting the water to where they needed it!

His gaze snagged on the horse blanket that Matty had pointed out to him, crumpled in the corner of the deck near the tiller. Sherlock swept it up and threw it forward, across the flames, keeping hold of one corner so that the blanket didn't slide off into the water. Smoke rose from underneath, but no flames. Sherlock pulled the blanket back towards him. Half of the fire was out, suffocated by the thick material, but tiny ripples of flame were still investigating the seams in the boat's construction.

Matty cried out as another oil lamp hit the edge of the boat near Sherlock's head and bounced into the river, where it sank, spitting and hissing as the wick touched the water. Sherlock whirled round and dipped the blanket over the side of the boat, making sure he kept a tight grip on it. Before it became too saturated, he pulled it out and heaved it across the wood again. This time the flames hissed as the sodden material extinguished them.

Sherlock glanced up at the bridge as the narrowboat pa.s.sed beneath it, expecting a third oil lamp to come hurtling down on to his head, but their a.s.sailants appeared to have no more. Instead, Sherlock was shocked to see a body plunging down towards him. Clem had jumped. The thug hit the roof of the narrowboat, cracking the wood with his boots. He fell backwards on to the deck. Pulling himself to his feet, teeth clenched and eyes gleaming, he advanced towards Sherlock. Reaching down with his right hand, he pulled a wickedly curved knife from his belt.

'You thought you could break into our barn an' get away with it?' he snarled. 'You was seen running off from the blaze like the rat you are.' He reached for Sherlock's hair with his left hand. 'Prepare to meet your Maker!'

Sherlock backed into the corner of the tiny deck area, feeling the breeze as Clem's flailing fingers pa.s.sed in front of his eyes. The man was so close that Sherlock could smell the rank, sweaty odour rising from his rough clothes and see the dirt ingrained beneath his chipped fingernails.

Clem lunged forward and wound his fingers into Sherlock's hair, pulling the boy forward. Sherlock couldn't help crying out at the pain as his hair was almost yanked out of his scalp. For a moment, bizarrely, the memory of Albert tearing clumps of gra.s.s out of the riverbank filled his mind.

Clem pulled Sherlock against his shirt and gazed down into the boy's eyes. Sherlock could feel Clem's right hand coming up towards his throat, holding the knife. He was seconds away from having his throat slit open, and he didn't even know why!

Something slammed against Clem's back. Clem's eyes widened in shock, and Sherlock felt the tight grip on his hair relax. He took a step backwards, pushing Clem away with both hands. The man didn't resist, but staggered back before shuffling round, taking exaggeratedly careful steps.

Matty stood behind Clem. He was holding the boathook raised in both hands. For a moment Sherlock couldn't quite work out what had happened, and then, as Clem turned fully towards Matty, Sherlock could see a deep and b.l.o.o.d.y gash running down the back of his head from the crown to his thick, bullish neck. The skin was split open, and Sherlock could see white bone beneath the blood. Matty had hit him squarely on the back of the head with the boathook.

Clem took a step forward towards Matty, and then another. He raised the hand that held the knife, but he didn't seem to know what to do with it. He gazed stupidly at the knife, and then he toppled sideways, off the narrowboat and into the river, like a falling tree. The splash as he hit the surface of the water reached up almost as far as the bridge. For a moment Sherlock could see Clem's face as he sank, and the expression of disbelief in his mad eyes, and then he was vanishing into the murk and sediment at the bottom of the river. His hands were the last to disappear, fingers waving like weeds in the current, and then they too were gone.

CHAPTER EIGHT.

Sherlock was still shivering by the time the sun was fully above the horizon and hanging in the sky behind the black silhouettes of the trees like an overripe fruit. Clem's grip on his shoulder had left a deep ache that radiated downward into his back. If he looked he was sure he would find bruises there five oval bruises left by four fingers and a thumb.

After the attack, after Clem had sunk in the water and his companion had run off, Matty and Sherlock had just stared at each other for a few moments, shocked by the sudden violence and the equally sudden cessation.

'He wasn't trying to steal the boat,' Matty had whispered eventually. 'He was trying to destroy it. I've had coves trying to steal it before, but why would someone want to burn it? I never seen 'em before! What have I ever done to them?'

'They wanted me,' Sherlock had said reluctantly. 'That was one of the men from the warehouse. I think he was in charge at least, in charge of the men who were there. The Baron that they talked about is really in charge. He must have seen me leaving the warehouse when it was burning and realized that I'd overheard them. But I don't know how they tracked us down to the barge.' He had shaken his head in disbelief. 'What is it that they're doing that they're willing to kill us to protect their secret? What is that that important?' important?'

Matty had just stared at Sherlock as if he'd been betrayed, then he had abruptly turned away and flicked the rope to get the horse moving again.

And now, as the sun was rising and Sherlock's shoulder was aching like a rotting tooth, they were coming in to Guildford, and he still hadn't worked out what it was he was meant to know. All he had was questions, and the attack had just added to them.

A small pack of scruffy dogs was following them along the riverbank, watching in the hope that they might throw some sc.r.a.ps of food away. Sherlock smiled briefly, thinking how much like Matty they were in that regard. He glanced forward, to the back of Matty's head, and the smile faded from his face. He had put the boy's boat at risk the only real home that Matty possessed. Worse, he had put the boy's life life at risk. And for what? at risk. And for what?

People were beginning to appear at the side of the river now. Some were obviously on their way into or out of town, using the riverbank as a convenient route, while others were sitting on boxes and dangling makeshift fishing rods into the water, hoping to catch some fish for their breakfast. Smoke was rising into the sky ahead of them, as Guildford's occupants set about their cooking for the day. Buildings began to line the banks: some makeshift shacks formed out of wood that had been nailed together at various angles and some more substantial affairs of brick. Stone paving slabs appeared, patchy at first but eventually forming a pavement of sorts along the edge of the water.

After a while, as they approached a collection of warehouse-like buildings cl.u.s.tered together on the riverbank, Matty began to pull on the rope. The horse slowed, and the narrowboat coasted gently into the bank. Matty had timed it well: they ended up coming to a rest just by a large iron ring that had been set into one of the slabs. Sherlock expected him to wrap the rope about the ring, but instead Matty reached into the bows of the boat and pulled out a chain which appeared to be fastened to an eyelet sunk into the wood. He threw it to the bank and jumped after it. Winding the chain about the iron ring, he took a large old padlock out of his pocket and slipped it through several links of the chain.

'Can't trust anyone round here,' he muttered, still not looking at Sherlock. 'A rope they could cut, but a chain and padlock'll take them a pretty time to get through. More time than the boat's worth, I reckon.'

'What about the horse?' Sherlock asked.

'If he can find someone who'll treat him better than me, he's welcome to go,' Matty said. He took a step on to the gra.s.s, then looked back at Sherlock. His expression wasn't exactly apologetic, but at least he was willing to make eye contact now. 'He's too old and lame to pull a plough or a cart,' he explained. 'A boat's about his limit, and even then he's slow. He's not worth stealing.'

'I'm sorry about what happened,' Sherlock said awkwardly.

'S'not your fault,' Matty said, wiping a sleeve across his mouth. 'You've fallen into something, and it's got hold of you. I'm just caught in it as well. Best thing to do is try and get ourselves out as quickly as we can, and move on.' He looked around. 'This is Dapdune Wharf,' he said. 'If we get separated, which is likely, then just remember to meet back here. I won't go without you.' He looked critically at Sherlock. 'An' I'm pretty sure you can't leave without me. Now, what was the name of that cove you was lookin' for?'

'Professor Winchcombe,' Sherlock said.

'Then let's go and find him. And maybe we can get some breakfast on the way.'

Together, the two boys headed away from the river, along a path that promised to lead them out on to a larger thoroughfare. It took them an hour of walking, and asking several pa.s.sers-by, before they discovered that Professor Winchcombe's house was in Chaelis Road, which led off the High Street, and then another half an hour to find the High Street, which led uphill away from the river and was lined with two- and three-storey shops constructed out of black wooden beams with white plaster infill. Signs hung outside: wooden plaques with paintings of fish, bread, vegetables and all manner of other goods. The people walking up and down the street and looking in the windows were, for the most part, dressed better than the people in Farnham. Their clothes were made of finer fabrics, trimmed with lace and ribbon, more colourful and cleaner than Sherlock had seen for a while.

A few stalls selling fruit and cold cooked meat were located at the bottom of the High Street, along a waist-high wall that separated the town from the river. Matty was about to creep along the wall behind the stallholders, and look for food that had fallen off the stalls, but Sherlock just walked up and used some of the dwindling resources that Mycroft had sent him to buy them both some breakfast. Matty glanced at him suspiciously: Sherlock got the impression that Matty thought food somehow tasted better if he hadn't had to pay for it. As far as Sherlock was concerned, food tasted better if it hadn't been rolling in the dust or if you hadn't had to fight a dog for possession of it.

Chaelis Road was halfway up the High Street, and both boys were out of breath by the time they got to the point where it started. The road curved sharply out of sight and Sherlock set off along it, but paused when he realized that Matty wasn't following. He turned and gazed questioningly at the boy.

'What's the matter?'

Matty shook his head. 'Not my kind of place,' he said, eyeing the tall houses and well-kept gardens that lined the road. 'You go ahead. I'll wait here.' He looked around. 'Somewhere round here, anyway.'

Sherlock nodded. Matty was right the presence of what Mrs Eglantine had described as a 'scruffy street Arab' would probably cause them problems. Brushing as much dust from his clothes as possible, he moved on.

The house he was looking for was just round the curve. He pushed the gate open and approached the door, which was protected by a Greek-style portico. A bra.s.s plate was screwed on to one of the pillars. Engraved on it were the words: 'Professor Arthur Albery Winchcombe. Lecturer in Tropical Diseases'.

Before nerves could get the better of him, Sherlock tugged at the bell pull.

A man in a severe black suit and grey waistcoat opened the door. He stared down at Sherlock through tiny gla.s.ses that barely covered his eyes.

'Is Professor Winchcombe at home?' Sherlock asked.

The man Sherlock a.s.sumed he was a butler paused for a moment. 'Whom shall I say is calling?' he asked eventually.

Sherlock opened his mouth, about to introduce himself, then hesitated. Perhaps he would be better off invoking someone else's name someone that the Professor had heard of. Mycroft, perhaps? Or Amyus Crowe? Which one would be best?

In the end, he chose one at random. 'Please tell the Professor that a student of Mr Amyus Crowe wishes to consult him,' he said.

The butler nodded. 'Would you care to wait in the sitting room?' he asked, holding the door open. Treating Sherlock as if he was royalty rather than just a somewhat dishevelled and nervous boy, he gestured towards a door across the hall.

The wallpaper lining the room was covered in paintings of tall, thin plants that Sherlock didn't recognize, like ma.s.sive gra.s.ses. They seemed to have rings round their stalks, set at equal distances all the way up. He found himself fascinated by them, and he was still looking at them when the door opened and a man entered the room. He was small smaller than Sherlock and his stomach protruded as if he had a cushion shoved under his jacket. He wore a funny little red hat on his head with no brim or peak: just like a short, fat tower made of red silk.

'Bamboo,' he said.

'Pardon?'

'Those plants on the wallpaper. Bamboo. It's a woody perennial evergreen of the gra.s.s family. I spent quite some time in China in my youth, and became very familiar with it. Bamboos are the fastest growing woody plants in the world, you know. The bigger ones can grow up to two feet a day, under certain conditions. The wallpaper itself is Chinese, by the way. Ricepaper.'

Sherlock wasn't sure he understood. 'Paper made from rice rice?'

'A common misconception,' the Professor replied. 'In fact, ricepaper is made from the pith of a small tree, Tetrapanax papyrifer Tetrapanax papyrifer.' He c.o.c.ked his head to one side. 'You say you are Amyus Crowe's student?' he asked. His eyes, behind his gla.s.ses, were bright and bird-like, alive with curiosity.

'Yes, sir,' Sherlock replied, feeling strangely as if he was back at Deepdene School.

'I received a letter from Mr Crowe this morning. Very odd. Very odd indeed. Is that why you are here?'

'Was the letter about the two dead men?'

The Professor nodded. 'Indeed it was.'

'That's why I'm here. I heard Mr Crowe say that you were an expert on diseases.'

'I specialize in tropical diseases, but yes, my area of expertise covers most of the serious contagious illnesses, from Tapanuli fever and the Black Formosa Corruption to cholera and typhoid. I understand that these two men may have died of some unknown illness.'

'I'm not so sure.' Sherlock scrabbled in his jacket pocket and pulled out the envelope that had contained Mycroft's letter, and now contained a sample of the yellow powder. 'I collected this from near one of the bodies, but I know it was present on both of them,' he said in a rush. 'I don't know what it is, but I think it's connected to the deaths. It might be poisonous.'

The Professor held out his hand for the envelope. 'In that case I will treat it carefully,' he said.

'You believe me?' Sherlock asked.

'You've come all this way to see me, so I a.s.sume you are taking this seriously. The least I can do is to take it as seriously as you. And besides, I know Amyus Crowe and I believe him to be a man of integrity. I cannot imagine him taking on a student who would indulge in practical jokes.' He smiled suddenly, and his face was transformed into something cherubic. 'Now, let's go and take a look at this sample that you've brought me.'

He led the way across the hall and into another room. This one was lined with books, and had a large desk over by the window where the light was best. Sitting on a pad of green blotting paper on the desk, among scattered papers and journals and a burning candle, was a microscope.

Professor Winchcombe sat in a leather-backed chair behind his desk and gestured for Sherlock to pull up another chair by his side. He pulled a sheet of blank parchment from a drawer and put it on the blotter beside the microscope, then cautiously teased the flap of the envelope open with a paperknife and poured the contents on to the parchment. Within moments he had a pile of yellow powder in front of him. With the tip of the paperknife, he collected a few grains of the powder and transferred them to a gla.s.s slide that was already clipped to the stage the flat plate beneath the objective lens. He adjusted a mirror beneath the stage, angling it so that it reflected the light from the candle up through a hole in the stage and through the gla.s.s slide to the lens. As Sherlock watched, trying not to breathe too hard so that he didn't disturb the powder, the Professor stared into the microscope, twisting the coa.r.s.e and then the fine adjustment k.n.o.bs, bringing the grains into focus.

'Ah,' he said, and then, 'Um.' He took his red hat off, scratched his head, and replaced the hat exactly where it had been.

'What is it?' Sherlock whispered.

'Bee pollen,' the Professor said. 'Quite unmistakable.'

'Bee pollen?' Sherlock repeated, not sure whether he'd heard correctly or not.

'Have you ever studied bees?' the Professor asked, leaning back in his chair. 'Fascinating creatures. I commend them to you as a subject for serious investigation.' He removed his gla.s.ses and rubbed his eyes. 'They collect pollen from flowers and carry it to their hive.'

'What is is pollen?' Sherlock asked, feeling strangely disappointed. 'I've heard the word before, but I've never been quite sure what it meant.' pollen?' Sherlock asked, feeling strangely disappointed. 'I've heard the word before, but I've never been quite sure what it meant.'

'Pollen,' the Professor said, 'is a powder consisting of microgametophytes, which produce the male gametes, or reproductive cells, of seed plants. The pollen is produced by the stamens, or male reproductive organs, of flowers and carried by the wind, or by foraging insects, to the pistil, or female reproductive organs, of another flower of a similar nature. There they fuse to form a seed.' He examined his gla.s.ses, then slipped them back on his nose. Sherlock tried to sort through what the Professor had told him, but realized that the man was speaking again. 'In the case of bees, they collect pollen from flowers and carry it back to the hive in ball-like ma.s.ses on their hind legs. The benefit to the plant, of course, is that as the bee travels from flower to flower it drops some of the pollen from the stamen of one flower on to the pistils of another, thus a.s.sisting the reproduction. Now, on the bees' upper hind legs they have minute hairs that act as a basket where the bee rolls up the pollen dust grains and mixes it with nectar to form a ball. And that is what we call "bee pollen".'

'And it's safe?'

'For most people, yes, although a few unfortunates do have a physical aversion to it.' He leaned back and thought for a moment. 'Could that have caused the boil-like swellings that Mr Crowe described in his letter? Hmm, I doubt it. Reactions to pollen tend to be more like rashes than boils, and to find two men chosen presumably at random who have such a sensitivity would be unlikely.' Suddenly he hit the desk with his hand. Sherlock jumped. 'Of course! I'm ignoring the obvious answer!'

'Obvious?' Sherlock racked his brains. What was the obvious explanation for boil-like swellings when bees were involved? And then the realization burst on him like a flash of lightning. 'Stings!' he cried out.

'Well done, my boy. Yes, bee stings. Very virulent stings, at that. Most bees in this country, at least, have stings that cause pain and a slight raised spot, but nothing like the boils that Mr Crowe described.' He glanced at Sherlock. 'You must have seen them too. How large were they?'

Sherlock held up his right hand. 'About the size of the end of my thumb,' he replied.

'Indicating a very virulent strain of venom, and perhaps a very aggressive form of bee.'

'How do you know so much about bees?' Sherlock asked.

The Professor smiled. 'I told you that I spent some years in China. The Chinese have been keeping bees for several thousand years, and I discovered that honey is highly prized by them for its medicinal benefits. According to the records in the great medical work Bencao Gangmu Bencao Gangmu, or The Compendium of Materia Medica The Compendium of Materia Medica, which was written by a man named Li Shizhen three hundred years ago, honey has the ability to tone the spleen, alleviate pain, remove toxic substances, reduce vexation, brighten the eye and prolong life.' He looked away from Sherlock, towards the wall, and Sherlock got the impression that he was remembering things that had happened many years before. 'Here in Great Britain we are used to the rather docile European honey bee, Apis mellifera Apis mellifera. The Asian rock bee, Apis dorsata Apis dorsata, is considerably more aggressive and has a much more painful sting, and yet still the Chinese keep them and harvest honey from their hives. Unlike our hives, which are shaped like bells, the Chinese use hollowed-out logs or woven cylindrical baskets to keep the bees in. Sometimes you could see the Chinese peasants carrying their beehives up into the mountains, two at a time, slung on the end of bamboo poles which they balanced on their shoulders. I remember watching them climb, with the bees buzzing around them like a cloud of smoke.'

A cloud of smoke. The words. .h.i.t Sherlock like a blow between the eyes.

'That's what it was,' he breathed.

'What?'

'I saw a shadow moving away from one of the bodies, and my friend saw the same thing coming out of a window where the other body was discovered. It must have been the bees!'

The Professor nodded. 'They would have had to be pretty small for you to mistake them for a shadow, and probably dark in colour, rather than the bright yellow and black of your typical b.u.mblebee. I believe there are African bees that are small and virtually black. They too are very aggressive.'

'Would you do something for me?' Sherlock asked.

'Of course.'

'Would you write a letter to Amyus Crowe, telling him what you believe caused the deaths of those two men? I'll take it back to Farnham and give it to him.' He looked away from the Professor, feeling his face flush. 'I think I'm going to be in trouble with my aunt and uncle when I get back, and that might save me from getting punished.'

The Professor nodded. He tipped the yellow powder the harmless yellow powder, Sherlock had to remind himself from the sheet of parchment on to his blotter. Reaching for an inkwell on the edge of his desk, he withdrew a quill and began to write on the parchment. His handwriting was spidery but Sherlock could just make out the words.