‘No,’ agreed Bartholomew. ‘The fatal wound came from Aristotle. His Principal was blessed with an unusually thick skull, but it seems Browne has an unusually thin one.’
There was nothing to be done for Browne, except to wrap him in his cloak ready to be taken to St Botolph’s Church. Bartholomew and Michael worked in silence, the only sound being Walkelate’s shocked whimpers, as his eyes went from the body to the damage that had been inflicted on his exquisite carvings. He did not seem to know which was worse.
‘Will presenting Browne as the villain be enough to avert trouble today, Brother?’ Bartholomew asked.
Michael rubbed his eyes with fingers that shook. ‘I do not know. It would have been better to present a living suspect – a corpse looks contrived. And Batayl will deny the charges, of course.’
‘Browne was lying,’ said Walkelate, regarding the body with a mixture of anger and distress. ‘He denied killing Northwood and the others, but I wager you anything you like that he did poison them as they experimented.’
Bartholomew looked at him sharply. ‘What makes you say they were poisoned? We have not mentioned that theory to anyone else.’
‘Other than Julitta, apparently,’ muttered Michael. ‘And possibly Ayera.’
Walkelate shrugged. ‘Four men do not die of natural causes all at once, and Dunning told me that you found no signs of violence on their bodies. What else is left but poison?’
‘Everyone else seems to believe that God or the Devil is responsible.’ Bartholomew narrowed his eyes. ‘Yet Clippesby and Riborowe said those four dead men met here on a regular basis, and it is unlikely that they could have done it every time without you noticing. You spend all your time here, after all. And the answer is that you were experimenting with them!’
‘Steady on, Matt,’ murmured Michael. ‘You cannot accuse everyone of–’
‘But I was not with them the night they died,’ cried Walkelate. ‘How could I have been? I would have been poisoned, too. I was in here with my artisans, listening to the singers that Holm hired as we polished the shelves.’
Michael’s jaw dropped. ‘But that answer implies you joined them on other occasions! Why did you not mention it sooner? We have been desperate for clues about their deaths, and your testimony might have helped.’
Walkelate hung his head. ‘I did not dare, Brother. I was afraid you would stop me working on the library if I admitted to sharing their passion for invention. But I was going to confess tonight, when this place is open and nothing else will matter.’
‘So tell me now,’ said Michael angrily. ‘What were you doing? Making lamp fuel?’
‘Yes,’ admitted Walkelate. ‘I am sorry, Bartholomew, I know you are working to that end, too, but I did it to raise money for the library. Vale said that whoever discovers clean-burning fuel will be rich, and Northwood invited me to join their team when I caught them in the garden one night.’
‘Why did he invite you?’ demanded Michael suspiciously.
‘Because I was able to make several useful suggestions,’ explained Walkelate. ‘Such as adding rock oil and red lead. He said my extensive knowledge of alchemy was invaluable.’
Michael scrubbed tiredly at his face. ‘We shall discuss this later, when you do not have bookcases to repair, and I do not have a “cataclysmic” raid and rebellious scholars to worry about.’
‘Thank you, Brother,’ said Walkelate gratefully. ‘I shall go to round up my artisans at once, and see what can be done to disguise Browne’s handiwork.’
While the architect disappeared about his business, Michael and Bartholomew carried Browne to the street, where the monk ordered three passing beadles to take the body to St Boltoph’s. The physician half listened to Michael telling his men what Browne had overheard, and let his mind wander to an image of Northwood, the London brothers and Vale conducting their experiments in the overgrown garden, and of Walkelate helping with new ideas. Then he thought about the substances Walkelate had recommended, and tendrils of unease began to writhe in his stomach.
‘Oh, no!’ he breathed, as understanding came crashing into his mind. ‘They were not making lamp fuel – you do not need red lead and rock oil for that. They were concocting something else.’
‘What are you talking about?’ demanded Michael irritably. ‘I am too tired and fraught for–’
‘Wildfire! Rock oil is what makes wildfire sticky and unquenchable.’
‘I sincerely doubt Walkelate and the others were making that! They–’
But Bartholomew’s mind was racing. ‘Northwood would have been interested only from an alchemical standpoint, but Vale liked money. And now we have Walkelate, eager to raise funds for his library. Of course, there are other clues that prove they were dabbling with weapons …’
‘There are?’ asked Michael warily.
‘Warden Shropham told us that Walkelate is the son of the King’s sergeant-at-arms, and such men will certainly receive military training in their youth.’
‘So did I, but it does not make me a candidate for inventing incendiary devices.’
‘The ingredients for lamp fuel must not be expensive,’ Bartholomew forged on. ‘If they are, the invention will be useless, because no one will be able to afford to buy any. But military commanders rarely baulk at the cost of materials for weapons.’
‘So? I do not understand your point.’
‘The compounds Northwood was using were expensive, because he was stealing exemplar money to pay for them – Ruth told us.’
‘We did not find money in his cell,’ conceded Michael. ‘So it clearly was spent. But Walkelate just said Browne was lying – that our villainous Batayl man poisoned Northwood and his cronies. Why would Walkelate–’
‘To prevent you from seeing the truth, of course! And maybe it was he, not the raiders, who demanded the formula from Rougham and me. He probably recruited others to help him waylay us. Such as Holm – he is greedy and ruthless.’
‘Matt!’ cried Michael. ‘You are allowing dislike to interfere with your reason. Calm down and–’
‘I am perfectly calm! And if we dither over this, blood will be spilled.’
‘It will be spilled if we go adrift with erroneous assumptions,’ Michael shot back. ‘But if you are right, and Walkelate and his cronies were striving to invent something sinister, they would not have chosen Holm to assist them. They would have picked Gyseburne – a man fascinated with urine, which is combustible.’
‘No, it is Holm. He is Walkelate’s friend, who provides him with remedies to rid the library of unwanted smells.’ More solutions cracked clear in Bartholomew’s mind. ‘And if they were making wildfire, they will have used some very dangerous materials as well as expensive ones – such as red lead. They were poisoned, but they did it to themselves!’
Michael regarded him dubiously. ‘Then why did Vale have an arrow in his back?’
Bartholomew thought quickly. ‘Because when Walkelate tried to conceal the bodies by dumping them in the pond, Vale got caught on that platform. The others would have surfaced eventually, because of gases, but Walkelate probably does not know that. He must have shot the arrow in an effort to haul Vale free, and–’
‘That seems excessive,’ said Michael in distaste. ‘Why not just wade in and grab him?’
‘Impossible – the water is too deep. And perhaps he was in a hurry, because he was short of time – Browne often went fishing in the mornings. Or more likely, he did not want to immerse himself in toxic water.’
‘How would he know it was toxic?’
‘I think they dumped their failed experiments in it. It would certainly explain why I was ill after falling in, why your beadles felt unwell after dredging for bodies, and why the riverfolk and Batayl were sick after eating its fish. There is Agatha’s testimony, too.’