Chapter Nine - The Route Through the Maze

When the Heads of Houses gathered in Dumbledore's office the following evening Celeste accompanied them. Snape summarised the main points of his meeting with Sprout and Celeste, and spoke in detail about the work on the variant of the Wit-Sharpening Potion. He handed over to Sprout who explained the position regarding Stipa macropungen's stocks and cultivation. She ended by saying that Celeste had some important ideas and could also bring them up to date about the patients.

"Celeste, let us now have your news" Dumbledore said kindly.

"Right" Celeste said a little nervously. "The hospital wing is running at just under seventy-five percent full. And that is with three students – Russell Dunwoody, Holly Van Ryssen and Rachel Costello having been taken home by their parents."

"Hang on" Flitwick interrupted, "I thought both the Costello girls had gone."

"Yes, they have" McGonagall cut in, "but Sally Costello was not ill, the parents just wanted both girls to return home. Sorry Celeste, please go on."

"I've got Argus to rope off an exclusive route to the hospital wing for visitors" Celeste continued. "For parents, Mediwizards and so forth, so that it's not so easy for them to go wandering about the school. It links to the West Door and he's put up notice boards discouraging others from using it. I've also got Argus to maintain three disinfectant mats – a very big one for arriving carriages to park on, one across the West Doorway and one across the Main Entrance. I don't want to raise your hopes too much" she added, seeing their intrigued looks. "I'm not a Medic as you know, but it seems to me that the disease agent is quite possibly an air-born thing, in which case these floor pads won't get to it. Also, the contact time with disinfectant pads is usually too short to kill many bugs, so you may be wondering why bother with them. It's because they do help to bring home to visitors the need to take precautions, and the point that both they and all of us may be carriers of infection. It may be window dressing up to a point, but I think it's window dressing with a message."

"They sound an excellent idea" Dumbledore said. "I am just astounded that you have managed to get Mr Filch to do so much, and so soon."

"Ah, well – (Celeste smiled rather shyly, looking at Snape) – I had some help."

"Mr Filch is co-operating very readily" Snape said smoothly. "Since I discovered his favourite spectator sport is swimming, he and I have got on like a house on fire. Naturally he is very much in favour of any procedure that curbs the spread of muddy footprints about the building, so he was quite easily persuaded."

Everyone except Celeste looked puzzled about Snape's 'swimming' comment but dismissed it as merely some form of in-joke. However the point about muddy footprints was not lost on them; Filch was famous for being manic about mud. Snape's powers of persuasion were also legendary; as was his fondness for cryptic comments.

"Anything else, Celeste?" Dumbledore asked.

"Yes, I've just thought of something, Headmaster" the trainee replied anxiously. "The back stairs to the hospital wing – does the staircase move?"

"No" Flitwick assured her. "We broke Rowena Ravenclaw's bewitchment of that staircase many decades ago, as it is the most direct route from the Quidditch pitch. Didn't want it throwing staff off course when hurrying an injured child up to Pop–" but he was cut off in mid sentence by the sudden arrival of Poppy Pomfrey herself.

"Virginia Rushbrooke is developing skin lesions" she announced.

A flurry of question greeted this remark. "She hasn't coughed for over a day, now" Pomfrey went on, "but these lesions remind me of Miscanoblastus Ruber."

There were gasps. Miscanoblastus Ruber was a rare but much feared ailment in the magical community. It was a virulent skin disease. Deep pink, blister-like surface lesions were produced which eventually burst, releasing some sort of disease agent into the atmosphere which was then breathed in by new victims. The lesions were extremely difficult to heal with spells – new ones tended to break as fast as old ones were sealed. Septicaemia was often the result, accompanied by a high proportion of fatalities.

"I think" said Dumbledore, "we will adjourn for twenty minutes. I want to take a look at Virginia. We will reconvene here at a quarter past ten."

Dutifully at ten-fifteen the staff reassembled in Dumbledore's office, while Madam Pomfrey remained with her patients. The Headmaster looked very grave.

"This, I think, is not exactly like Miscanoblastus Ruber" he informed them. "Or it is not like the disease used to be. Yet in some ways it resembles it."

"The most effective way to treat Miscanoblastus Ruber" Snape muttered, "is with Zenthem gum in an ointment. This disease, whatever it is, has moved from the lungs to the skin."

"Then it's moved through the blood stream" Celeste ventured.

"Yes!" Snape said. He looked triumphant. "Phoebe's Tresses" he said in a stage whisper to Sprout.

"Silverweed" she whispered back. "Spartina argenta. But we don't have any. Can we buy enough of it? We can't grow it, can we."

"Erm, we may be able to" Celeste put in.

"We did try that" Sprout assured her. "It was some forty years ago. I was a young teacher here, then. The Headmaster will remember. Winter cultivation wasn't exactly a success was it, Headmaster."

"No" Dumbledore agreed. "The conclusion was our winters are just too cold this far north."

"Well, I'm going to have to heat a greenhouse for the Stipa" Sprout pointed out. "Might as well get cracking on both plants. I think I'll set up two greenhouses for each one to start with, although I fear the two for the silverweed will be redundant. Still, they can always be turned over to more Stipa –"

"Professor, hang on a moment please." Celeste's voice was urgent and she put out a hand to touch Sprout's arm. "Remember when we spoke about day-length depended plants? We talked about vlox and ferbenona, and silverweed too. Do you remember my mentioning Iulio Silvestre, the candidate from Brazil?"

"I do" Sprout agreed. "Candidate Number Two, he was. Say it all again please, Celeste – describe it to everyone."

"It was the day of the interviews" Celeste explained. "We chatted while Candidate Number Five was being seen. Iulio was keen on Potions, but Herbology was his favourite subject, and he was going over in his mind what would grow here, compared to South America. I thought he wouldn't be able to grow all that he'd been used to, because of the cold. He explained that although that was largely true, temperature wasn't the only factor. Some plants could be found growing high in the mountains near the equator even though it could be very cold. It was light levels that mattered. Day length. Not temperature. Silverweed – Phoebe's Tresses – is one of those plants. Even in the toughest spots in the Andes it copes, developing long, twisting roots that reach way down through the barren rocks. It grows well in the cold as long as it has enough light."

"Long … twisting … roots" Dumbledore repeated, turning from Celeste to look pointedly at Snape and then at McGonagall. "I though her words were a long and twisting route" he added in a murmur, "but she said root. I didn't understand." He cleared his throat and spoke in general to the meeting. "Mr Silvestre, via you Celeste, has given us a ray of hope I think. If we can cultivate the plant, you can make the potion, Severus?"

"Yes, Headmaster" Snape concurred thoughtfully. "That will be of most effect at the transition stage, while the disease is migrating to the skin. Once the lesions are fully formed however, Zenthem gum would be more effective. The gum contains a concentrate of the active ingredient of Spartina argenta, but its extraction is quite a lengthy process."

"Then let us start simple" Dumbledore ordered. "Amy, Celeste, procure some Spartina and get the greenhouses in operation. I'm sure you can contrive to have them artificially lit and heated. Felix, you may be able to assist with charms to do that. Severus, make as much Silverweed Potion as you can. You can try Stipa macropungens as well, but not at the expense of silverweed. Minerva, owl Virginia's father at once, to alert him to his daughter's condition. Any questions?"

There were none; everyone was anxious to get things underway.

Virginia Rushbrooke was a child from a single parent family, her mother having died when she was four years old. It transpired that Virginia's father was also ill, and his short reply merely asked if the school could continue to care for his daughter. Although he didn't say so, he felt too unwell to try to find a hospital place for her, and he had a great deal of confidence in Hogwarts. Indeed, a somewhat irrational degree of confidence; and in this he was not alone. Since the victory over Voldemort, Hogwarts reputation was higher than ever. It was a factor that Celeste would soon come to marvel at, and to worry about.

Heating the greenhouses was not too difficult, but lighting them proved trickier. Flitwick made them as bright as Christmas decorations by filling them with fluttering golden fairies, but Celeste said this wasn't necessarily going to work. "It's not just the light, it's the frequency that matters" she said. "We haven't got a full spectrum here. Plants grow in sunlight where there is a much greater range of frequencies, and they just pick up what they need from it. Can you find fairies that give out light in the red and violet wavelengths? If we include a fair proportion of those it should improve things."

It did improve things and the plants began to burgeon.

Meanwhile, Snape's first brew of the Silverweed Potion eased the plight of many of the patients but it had little impact upon Virginia Rushbrooke. Sinistra, Hooch and Pomfrey took turns to clean her rupturing lesions and heal them with their wands, but it was an uphill struggle. And while they battled with her condition, Professor Vector's cough subsided and the Wilson twins began to develop lesions.

"This just goes to show the importance of Zenthem gum" Snape insisted. He was standing in Greenhouse Three, watching Celeste record the air temperature on a sheet of graph paper pinned to a board on the wall. She did this every hour; her pink Muggle pen accompanying her everywhere, hanging around her neck from its cord. "I wish I'd started that rat spleen extract now" he moaned.

"What's ailing you now, Severus?" Sprout asked, as she struggled in with a bag of compost.

"The potion's not much good against the lesions" Snape mumbled darkly. "The macropungens potion is helping the new cases, but the Silverweed's no good once the last stage is reached."

"Have you though of tolubutylene to extract the gum?" Celeste asked.

"Yes thanks" he replied curtly. "I don't want umpteen cauldrons full of that nasty bilge bubbling all over my Potions classroom."

Celeste thought. "What if we could distil it in a closed environment?" she asked.

"What is the point?" he countered acidly. "How would you propose to separate the tolubutylene from the extract? It's not exactly easy. Any significant traces of tolubutylene in the residual gum will poison the patient."

His tone was stinging but Celeste pressed on. "If we exploit the physical properties of both the tolubutylene and the extracted gum I think we can get an acceptably pure residue" she explained. "Below three degrees centigrade the gum hardens and becomes brittle. Its surface characteristics change and it turns from white to pale blue-grey. At that temperature the two substances have no affinity. There is zero adhesion between them; each instead is cohesive. We should be able to decant the tolubutylene and reuse it, leaving the hardened gum almost clean. Three washings – say – with clean water should reduce any residual tolubutylene to a safe level. OK, I know that's not the final product – the gum has to be warmed to soften it and make it workable. And it needs to be made into a paste so that it can be applied to the lesions–"

"You're gabbling, girl" Snape interrupted harshly.

Celeste knew this was true – the Potions Master was a powerful ally but he made her nervous at times. "Alright! My point is" she said angrily "I think my idea for a distillation method will give us a quick and workable process."

"Quicker than rat spleen?" Snape asked sharply.

"Much quicker than rat spleen! Hours, not weeks!"

"Are you proposing to turn our patients into guinea pigs?" he challenged.

Celeste thought hard about this. "If I am, do we have a better option?" she said finally.

His eyes bored into her. He didn't answer her question, but instead said quite menacingly "Very well, Witch. Let's evaluate – in detail – your whole plan…"

They sat in his office and Snape made a brew of comfrey tea. As she spoke and drew diagrams for him, he looked at her strangely at times. He could no longer see the 'spoiled, rich bitch' who drove the borrowed sports car, nor the 'tomboy' who had joked with Filch and Hagrid and let rip with the chainsaw, nor the 'obedient schoolgirl' who walked beside McGonagall. Here was more of the passionate logical thinker, but it was also mixed with a determined organiser – a woman who could put her foot on the accelerator and hold it there to get where she wanted to be.

Celeste found that talking her ideas through with Snape was very useful. He wanted to know how she knew so much about the physical peculiarities of tolubutylene and Zenthem gum, and she was able to explain that during her degree they had studied many curiously atypical effects such as super-conductivity and super-fluidity.

"Muggles know about – say – the super-fluidity of helium" Celeste explained, "but I also knew about the sharp transition point of tolubutylene and Zenthem gum affinity. I've still got my papers on it at home. Muggles don't have much use for those substances, certainly not together, so I didn't say anything about it. Wish in a way I had, now! We might not have to be struggling on our own with this remedy."

Although he knew little of Muggle science, Snape asked many searching and challenging questions, usually in his typically cold and bitter tones. It was uncomfortable but ultimately refreshing; at the end of it Celeste grinned to herself – having an enema must be like this, she supposed.

Snape realised his interrogation had been perhaps a little too brutal. "I'm sorry if you found me, at times, a trace over-brusque" he said off-handedly.

Over-brusque, she thought; that's putting it mildly!

Apart from the prefects' bathroom incident, Celeste had never heard him apologise for anything. "You also have a gift for understatement" she pointed out. "However, you brew a much better comfrey tea than I can. If I can have some more, I'm sure I can find it in my heart to forgive you."

He smiled his enigmatic smile, stood up and flicked his hair out of his face. "As you wish, Milady" he replied softly. "Comfrey tea coming up. Then I think we need to run these ideas past Albus and the other House Heads."

He set to immediately, to make a fresh pot of tea.

Dumbledore and the staff seated themselves in the front rows of desks in the Potions classroom and Snape stood facing them, his back to the blackboard. "The House Heads' had a meeting with the Headmaster earlier today" he began, "because we are on the verge of a development. Stipa macropungens – the plant that provides the variant of the Wit Sharpening Potion – is reasonably useful; as is the Silverweed Potion; but as you know we have a number of cases giving grave cause for concern, so we have been examining the possibilities of using Zenthem gum. It is the active constituent of silverweed – the silver-leaved grass Spartina argenta, and in concentrated form it works much more quickly that the traditional potion which itself is little more that stewed leaves with porcupine quills and burdock. Spartina is usually prepared as a water-based potion – that is what I have been making. The active ingredient, can, however be extracted using an acidified preparation of rat spleen; that is the classic method but it is very lengthy. Miss Lavelle has a plan for extracting it using tolubutylene. We never normally use tolubutylene; it is very poisonous. But it would give an exceedingly quick method of extraction. Miss Lavelle–" He extended an arm in her direction, summoning her forward. "Please. Outline your plan."

Celeste stood up and they swapped places. There was a cold haughtiness in Snape's manner as he gave way to her but he made way nevertheless, taking the seat she had occupied next to Dumbledore. She decided to put his coldness out of her mind; she had to get her point over, come what may.

"Right" she said. "Zenthem gum. What I'm thinking of is a distillation process like this…"

Taking a piece of chalk and speaking as she worked, she proceeded to draw a diagram on the blackboard. It showed a squat flask with the words 'heat source' beneath it. It was coupled to a device she labelled 'refluxing chamber'. She drew something that looked like a deep letter U inside the refluxing chamber and labelled it 'cellulose thimble – porous – holds sample'. The refluxing chamber was coupled tightly to the flask below and to a condenser she proceeded to outline above. Finally she indicated a side arm leading from a point near to the top of the thimble to just below it, connecting just above the flask.

"The tolubutylene is heated here" she said, resting the tip of her chalk on the squat flask. "It vaporises and rises, but when it reaches the condenser it cools and drips into the porous thimble, filling it up and soaking into the Spartina. Before the thimble overflows, the solution starts to pour into the side arm and siphons back into the flask. The mixture is heated, the tolubutylene vaporises leaving the gum behind and the process stars again. The gum itself does not vaporise – not at these temperatures – so the solution in the flask gets more and more concentrated. Eventually, say after three hours, we can remove the flask, cool it magically, the gum will harden and we can pour off the tolubutylene and reuse it. We can then scrape out the gum."

"And that's all there is to it?" Black asked, astounded at the simplicity of the process.

"Essentially yes" Celeste confirmed. Seeing their awed faces she added "Don't forget tolubutylene is poisonous. It needs very careful handling. Once we've poured off the excess, I suggest we actually wash the surface of the gum and blot it dry before we start to scrape it out of the flasks. However, in outline that is the process. In outline! But there are important details that remain to be worked out … so … before we go any further, I want to know whether you think we should proceed. Should we try this?"

"It will mean getting equipment. Can you get all this?" McGonagall asked.

"That's my next task – to find that out" Celeste replied. "I haven't checked it all yet in case you were against it in principle, and I haven't priced it. Professor Snape suggests we use this classroom. Will it be possible for Argus to run a water supply to a bench in here? We need a continuous flow of cold water for the condensers to work. It must be continuous, no break in supply."

"Yes, that can be done" Dumbledore said gravely. He looked as though he had already made up his mind and was merely waiting for everyone else to catch up and 'come on board'.

"What about tolubutylene being in the school? It's dangerous" Celeste reminded them.

"Then Potions classes must be entirely suspended" Dumbledore replied.

"The sixth and seventh years, Headmaster; perhaps they could help" Snape suggested. "This process will need manning. It is quite labour intensive."

"If you think they are up to it, Severus, yes, obtain the help of the senior students."

"They deal with some very dangerous substances already" Snape said. "Miss Lavelle and I do not intend to leave them unsupervised." Momentarily his voice tailed off. He paused and then said in a whisper to Dumbledore "The heavenly child! It's Celeste!" His ashen face was full of concern as he wondered just what fate had in store for the trainee. Dumbledore gazed at him and finally nodded.

"There will be fetching and carrying to do" Celeste was saying, "and the flasks must be watched to ensure nothing boils dry. I will explain the process to the students, and either I or a senior member of staff will be present while distillation is underway. Well, shall I start working on the details?"

"Is anyone against this?" Dumbledore asked, his blue eyes very piercing as he surveyed the room. There was silence. "There; you have your answer, Celeste. Let us try this – time is of the essence! Search out the equipment, Celeste, and list the prices, but do not worry about the cost. This will be afforded. And if necessary I will get the Ministry to deliver the items we need. Meanwhile I will speak to Argus immediately. Good work, everyone! Thank you!"

He smiled and muttered something to Snape as the meeting broke up and everyone prepared to leave.

"Where can I recharge my phone?" Celeste asked, as the staff filed out of the Potions classroom.

"At my brother's house" Flitwick said. "He lives at Glenallen and has electricity, a telephone, even a computer. Shall I take it over for you? I can nip over there tomorrow."

"Well, that's very kind of you, Professor, but I was sort of hoping to get it charged overnight tonight" Celeste explained.

"Then let's fly over together now" Flitwick suggested. "I'll introduce you."

"Thank you" she replied. "I didn't realise you knew about Muggle technology."

"Actually, err, my brother's house – his electric gadgets – there not exactly kosher, if you know what I mean" Flitwick said awkwardly. "Some of them have, er, been 'enhanced' shall we say. You won't mention it to anyone, will you."

"Like Arthur Weasley, next time I see him?" Celeste teased. "No, Professor. You can rely on my discretion."

The following day Celeste phoned a few contacts she had made whilst doing her degree. They were surprised to hear from her but were generally helpful. Her best contact proved to be an industrial chemist doing postgraduate research at Durham University. He had some modifications to suggest to the equipment she had in mind. He also gave her the details of a laboratory supply company in Milton Keynes. The firm was able to supply everything except the tolubutylene. She gave the firm her order; Ministry staff collected the items the following day, and delivered them to Hogwarts. Snape sent Hagrid to Knockturn Alley for a carboy of tolubutylene.

A mere three days later the weather had turned cold and the Potions classroom had turned into a mini industrial plant. Dumbledore did not want any time to be wasted. One side of the room was taken up by a new stone bench, upon which stood two long troughs – oil baths – into which flasks were suspended. A row of small fires burned beneath the troughs to heat the oil. Seventh year students sat tending the fires, watching the flasks, stirring the oil and checking its temperature. Celeste had realised it was too dangerous to heat the flasks directly. As she couldn't use thermostatically controlled electric heating elements, she had decided on oil baths as the safest way of keeping the flasks from developing hot spots and also keeping the naked flames away from any possible contact with the tolubutylene.

Above the flasks, condensed tolubutylene vapour dripped onto shredded silverweed leaves in two-hundred-and-fifty millilitre cellulose thimbles. Celeste had calculated that this was the optimum size for rapid extraction.

The students looked like laboratory technicians. They wore new white robes, goggles and disposable face masks. Their hands were protected by disposable gloves. White net hats covered their hair. They spoke very little and were attentive to their work.

Dumbledore slid into the classroom and quietly made his way to Snape, who then stopped stirring his gently bubbling cauldronful of macropungens leaves. "Yes, Headmaster?" he enquired softly.

"I have just heard from the Ministry" Dumbledore said quietly. "The wizarding hospital St Carmillus of Lellis is not taking any more admissions. It is only sixty-eight percent full but, due to staff sickness, they do not have enough staff to cope with a greater caseload."

"That is a rather frightening development, Headmaster."

"Indeed. Meanwhile here, Virginia Rushbrooke is a little better, and Dora Vector is being moved to hospital – St Philomena's, near to her family. They arranged it. Mediwizards are taking her now. Roger Styles and Gwen Naylor are slipping into the second stage. The Wilson twins are not doing well. Their parents are due here in an hour's time. I am going to speak to them and I would like Celeste to be there too. Can she be spared?"

"Yes, Headmaster. I can supervise the distillation."

Both wizards looked at Celeste. She was using a plastic wash bottle to rinse the gum surfaces inside a row of cooled flasks. The washings were stored in a cauldron set carefully aside for toxic waste which she or Snape treated with an Innocuoso spell at the end of the day. Except for the absence of goggles, she was dressed like the students. It was early in the day but her serious face already looked tired and drawn.

"I want her to help me to persuade the Wilsons to move their boys to hospital" Dumbledore explained. "Any hospital. Somewhere will be found. Minerva has owled the boys' parents about it, but they seem reluctant."

"Very well, Headmaster" Snape replied. He looked again at Celeste's weary face and there was a sadness in his eyes.