Huon particles?

How can the centre of this machine be filled with huon particles?

I lie on the floor of the blue box, trying to catch my breath again, the image of those particles haunting my memory. The last time I encountered them in their liquid form, not in the active, yet harmless, state they are in one of my distant rooms, they almost completely damaged me. Seeing them again is enough to create that creeping sensation up my throat, that fear which grabs me with unforgiving hands and refuses to let go.

When I feel a little stronger, I reposition myself in front of the Time Vortex with a single zap. I don't know what to do, but I do know that I have to do something.

And not just for me, but for the Doctor too.

"And the drumming is creeping up on the Doctor, Izzy, it's getting faster and faster and he needs to be prepared."

If only I knew what he needed to be prepared for.

I stare at the swirling screens that I'm able to access the Time Vortex through, trying to conjure up the right questions that will answer everything.

"What does the Doctor need to be prepared for?" I ask of it, more in hope than in expectation.

"Error. Non-applicable question." The voice of the Time Vortex is my voice, it has always been my voice, and although that was incredibly eerie at first, I have grown used to it. I guess it makes sense, since the Time Vortex did eat me.

"Right then," I mutter to myself. "What is this drumming?"

"Error. Non-applicable question," repeats my voice, the voice of the Time Vortex.

"Who is Mister Saxon?" I try again, pleading with the Time Vortex.

"Error. Non-applicable question."

"No!" I punch the Time Vortex with all the built up frustration that I carry inside me, watching as my holographic hand splinters off in millions of tiny orange sparks, before resuming its solidity or, at least, as solid as a holographic hand can be. "That can't be! How can someone exist that the Time Vortex has no knowledge of! Why won't you help me!"

"I can only show you what the universe knows," replies my voice in its Time Vortex-monotone form.

"Yeah, yeah, I know," I mutter, "I wasn't actually asking." I take a deep breath, tucking this latest information on Mister Saxon at the back of my mind. Instead, I focus on something else. I know what huon particles do. They convert people, they change them into something else, something non-human. And usually these non-human entities are highly deadly. So why are they here, inside a machine that simply takes the years away from a person's body? It's wrong, I know that, but it's not exactly deadly. And whatever Mister Saxon is intending to achieve with this machine, I doubt 'non-deadly' is the plan.

"Let's try another. Tell me a bit more about Professor Lazarus. What exactly has this machine done to him?"

The swirling screens slowly morph into a new image, and I sit a little closer, eager to see what the universe does actually know about this whole situation. Slowly, the image comes into focus, and I'm looking at the professor and his female sidekick again, only this time it's after the machine has done its work on the former. They are standing in his office once again, only this time they are looking out over the city of London, its lights gleaming and sparkling in the darkness.

"I grew up over there," says Lazarus, gesturing vaguely out the window. "A tiny flat above a butchers shop."

"It'll have a blue plaque there soon. 'Richard Lazarus lived here'."

"It's gone," he interjects, his voice distant and dreamy. "Destroyed in the war. The bombing."

"Of course," she replies, subdued.

"1940. Do you remember? Night after night. Explosions, guns, firestorm." His eyes never leave the view of the city below him, as if he is imagining how it was back then, his mind firmly locked in the past.

"My parents had sent me to the country by then."

He makes no indication that he heard her words. "When the sirens went, we'd go to the cathedral there. We used to shelter in the crypt. The living cowering among the dead."

"But look what you've built here, now," she stresses, and he finally turns to look at her. "You've built the foundations for an Empire. An empire we can rule together." She wraps her arms around his shoulders and pulls him in for a kiss, and for a while it seems like he is happy enough kissing her back, but suddenly the newly reborn man pulls away.

She looks up at him, surprised. "Well, what's wrong?"

He meets her gaze with a look of pure disgust, wiping the remains of the kiss off his lips with the back of his hand. Grabbing hold of her chin, he forces her head round until she is looking at her own reflection in the window. "Look at yourself, woman!"

"It's me who made all this possible! This is my triumph, and I will not be denied, not by you, not after everything I've done!"

"You backed me because you saw a profit," he contradicts, his voice icy cold. "Your concern was financial."

"Well, you want the money as much as I do!" Her voice is indignant, daring him to challenge her. She doesn't even notice that he's starting to look a little pale. "We had a plan. When the device is ready, I'll be rejuvenated, too. We could be rich and young and together."

"You'd think I'd waste another lifetime on you?"

She looks like he just slapped her in the face. "Did that process make you even more cruel?"

"No, my love. That I learned from you." His tone is patronising, and though she raises her eyebrows, she still remains silent. "You have a gift for it."

That pushes her over the edge. With that same voice of authority that she used with the Doctor, she says, "Then you know that I'll protect my involvement in this project. I'm sure Mister Saxon will be interested."

Suddenly, Lazarus gasps and pulls at his collar.

"What's going on?" she asks, concern filling every expression on her face, despite his earlier comments.

"It must just be," another spasm of pain wracks him, "ah!"

"What is it?"

"I'll be fine in a moment. It's probably just cramp." His back suddenly arches with a nasty cracking sound. He falls to the floor, tugging at his bow tie and writhing.

"Oh! Richard! Is it some sort of seizure? What should I do?" She starts to panic. "I don't understand what's happening! Richard?"

And suddenly, something very inhumane, something with a long neck and scales and sharp teeth, rears over the terrified woman, opens its large jaw, and lunges at her neck. And as her lifeless body falls to the ground, only a skeleton remaining, as the monster who attacks her morphs back into a man and walks off, barely looking at the body of his lover he has left behind him, the pictures around me fade to black.

I can only sit silently, trying to get my composure back after the horrifying scene before me. I have seen so many terrifying things in this universe during my travels with the Doctor, but nothing has ever hit me like this. This is my race, my people, and someone – this Mister Saxon – wants to make this cursed machine commercially available. I can't, and I won't, let it happen.

But I don't know exactly what has happened to Professor Richard Lazarus, and I need to, and urgently. I think back on the lesson on huon particles that the Doctor gave me, right at the beginning of our search.

"Huon particles can be created in an inactive and active form. The active form is the one at the centre of this ship. The inactive form can be created by using a hydrogen base. This form is liquid, and can only be activated inside a living being."

So that is why I was able to recognise the liquid pool in the centre of that machine as huon particles, even though they are different from my own. I had seen them before, when Donna was poisoned by them. That clearly means that the particles have become active in Lazarus. That much I could have guessed on my own. But why have they changed him in this way?

Think, Izzy, think.

And then the Doctor's voice floats back through my mind.

"…if the subject takes too much of the inactive form, they can die from poisoning, rendering them useless. It's all a question of balance."

"Yes!" Suddenly, everything makes sense. For reasons I don't yet understand, Mister Saxon has implanted inactive huon particles in the heart of that weird contraption. When Lazarus stepped inside and started up the machine, the huon particles got into his DNA and changed its pattern, or rather, brought out a dormant pattern that was already there before. That's what huon particles do. But Mister Saxon got the huon particle dosage wrong. Rather than putting too much in the machine and killing Lazarus, he put too little in and left him fluctuating between man and beast. And that was what he wanted. No one would go in that machine if the first person walked out as a monster. But the clever thing is that he looks human and healthy and, most importantly, rejuvenated, and now everyone wants to step inside.

My skin begins to crawl. I know I have to warn the Doctor, but there is no way I can contact him from here. But a quick scan of his whereabouts with the Time Vortex reassures me that he already knows and he's already trying to stop Lazarus from causing any more harm.

Mister Saxon wants to convert the whole human race into flesh eating monsters, but I will not let him. And neither will the Doctor.

And I rest my projection back against the central console and sigh with relief. If the Doctor already knows, then there is nothing more I need to do.

But there is something nagging at my mind. Obviously, this is not the first time that we've encountered huon particles recently. I knew there must be link between the different appearances, there has to be, but I could never see it. But now I know that Mister Saxon is involved, and that his plan here was to destroy the human race, maybe things will start to make sense.

I sink back into the heart of the tardis, close my eyes, and surrender my thoughts to the past.

There was the Racnoss first. I can see our fight clearly in my mind.

"Tell me where you got them from!"

That's me, growling at the Empress.

"Not from where. But whom."

That's her reply.

I open my eyes. Was she talking about Mister Saxon? What if she were? Was this mystery man behind the plot to drug Donna, awaken the huon particles using her body, and awaken the Racnoss at the centre of the earth, destroying humanity?

Now I'm thinking of the Royal Hope Hospital. The Doctor was so certain he would find huon particles there. What was it he said?

"If you had access to Huon particles, and you were trying to activate them in as many humans as you could, you would want to find a place where it would be possible to insert the inactive particles into liquid as easily and as often as you could. Furthermore, if you got the balance wrong, you would need a place where it wouldn't be suspicious for people to die."

"The hospital!"

But, all he found in that hospital was a human girl called Martha Jones and a plasmavore. No huon particles, no Mister Saxon, nothing. But another memory announces its presence in my mind.

"But the fact that they found traces of Time Lord DNA on Martha's face suspicious, and that they weren't specifically looking for a Plasmavore, shows me that, this time, they really had no idea who they were searching for."

"You think there was something else happening there, and the Plasmavore was a diversion for the Judoon?"

"I guess we'll never know. Just glad the humans there seem to be safe now."

"FINALLY!" And in that sudden moment, everything makes sense. I shoot my fist into the air in triumph, grinning widely. Finally, everything fits together.

For some reason I have yet to understand, Mister Saxon wants to harm the human race. When he discovered the Racnoss at the centre of the earth, or when they contacted him – which way round I do not know – he gave them the huon particles to active inside a human so that they could use their power to awaken their race. But the Doctor and I got in their way and the Empress and her children were forced to flee from this planet.

But Mister Saxon would not give up, and this time, he decided to use his weapons, his huon particles, directly against his enemy. Sneaking into a busy London hospital, he injected the particles into the patients, figuring out the correct dosage to give for his next project, killing innocent humans in his wake. But he was interrupted when the Judoon caught wind of suspicious activity there and somehow managed to flee the scene, leaving a plasmavore to explain away the events that had sent the Judoon there in the first place.

But he still got the information he set out to find. Now he knows exactly what dosage will leave a human fluctuating between two different forms. Now he's trying to convert humanity by using this machine, tricking people into converting themselves without him having to do it directly. And he located Lazarus, trembling during the war in Southwark Cathedral, and somehow conditioned this boy over the years to grow up to take on this project. How, I do not know – yet.

More than ever, I want to know who this Mister Saxon is, and why he has so much against my people. And why the universe knows nothing about him. But now, everything rests in the hands of the Doctor. Imprisoned in here as I am, there is nothing I can do to aid him. As much as it kills me.

And still, Jack's warning makes no sense to me...

It seems like an eternity passes before Martha and the Doctor step back into the Tardis again. Martha wonders off down one of my long corridors, looking for the bathroom, and when she is finally out of earshot, the Doctor turns to look at me.

"Before you say anything," I say, before he can open his mouth, "I know what happened with Lazarus. I know what he is, and what it means. Just tell me, did you finish it?"

He looks at me with a shocked expression, then slowly nods. "Yes. But how…?"

"Oh thank god!" I say weakly, sinking my projection down onto the steps in the corner of the control room. "Thank you, Doctor. I couldn't bare it if that was the way my people ended up."

He sits down next to me, gently. "Izzy, as long as I'm here, you never have to worry about your people. I will never let anything harm them."

"Thank you." I smile weakly. "How did you do it?"

"Oh," he says, stretching back in his seat, "you know? A bit of this, a bit of that. Southwalk Cathedral has great acoustics, did you know that?"

"Doctor! Tell me!"

He grins. "Later. First, tell me how you knew."

"I watched you. Through the Time Vortex."

"You were spying on me?"

"No!"

"Izzy?"

"Well…..maybe!" I laugh. "But it was for your own good. And at least we both know about Mister Saxon now. Saves you explaining everything to me."

"Woah, woah, back up! Mister Saxon? Who is this Mister Saxon?"

I look at him incredulously. "You mean, you don't know?"

"Well, Izzy, I think that is evident."

"Well, well, the human girl knows more than the Time Lord!"

"Izzy, I'm warning you…" But there is a twinkle in his eye.

"Ok, ok! I'll tell you." And I do, I tell him everything I learned, what I think I've pieced together, and what I think that means for us. While I talk, he gets up and paces the room. When I've finished, he continues pacing thoughtfully for a while.

In time, he turns to face me again. "We have to do something, Izzy. This is bad. This is very very bad."

"I know."

"Maybe we should…"

But at that moment, Martha enters the room, furiously jabbing at the buttons on her phone. "Doctor, any chance of getting signal in space?" she laughs.

He gives me a look, making me very aware that our conversation is not over, before turning his attention to Martha's phone and zapping it with his sonic screwdriver.

"Right, there you go. Universal roaming. Never have to worry about a signal again."

She stares at the phone, mouth open. "No way. This is too mad. You're telling me I can phone anyone, anywhere in space and time on my mobile?"

"As long as you know the area code. Frequent flier's privilege. Go on, try it."

But suddenly, the tardis begins to shudder. The Doctor's eyes flick to mine, and his next words are directed at me.

"Distress signal. Locking on. Might be a bit of…"

But the force of the trembling knocks them both onto the floor, while my projection zaps into the air to avoid slipping through solid flesh. But the Doctor continues to stare at me, and even though he couldn't say it fully and cannot finish his sentence because of Martha, I know what message lies between his words.

"Distress signal. Locking on. Might be a bit of a problem trying to detach ourselves now, so I think we have no choice but to go where the signal is taking us. Maybe that's a good thing. Maybe it's linked to Mister Saxon."

But when the trembling ceases, the Doctor simply says, "…turbulence." But I nod at him, and he knows that I understand.

"I want to come with you," I say, materialising next to him. Even though I know that I cannot.

"Sorry," he says, as if he were still talking about the turbulence, but I sense the sympathy underneath. "Come on, Martha. Let's take a look."

"Be safe, Doctor," I call after him as my doors close. I know the routine by now. He goes out and investigates, and I must always wait for him here.

As long as the universe is willing to keep us alive.