1

On the first page of the first chapter in every TARDIS's instruction manual, it is made boldly and explicitly clear how dangerous a device the chameleon arch is.

"The apparatus is intended to be deployed solely in the direst of circumstances," the manual reads, with the sort of menacing air that makes people think twice about disagreeing with it. "Due to the complex and innately unpredictable nature of full genetic metamorphosis, activation of the Chameleon Arch poses a significant risk to both operator and crew and should thusly only be relied upon as a final resort."

At this point the manual pauses – presumably for maximum dramatic effect – and offers up a few intricate blueprints, diagrams and statistics that, due to some odd evolutionary defect and the frankly offensive capacity of their brains, Time Lords are naturally predisposed to enjoy looking at.

"Even while not in use, the Chameleon Arch remains a hazard," continues the manual under the next header, adopting a sterner tone to refocus and calm the reader from the excitement of the diagrams. "Its extreme volatility leaves it at risk for inadvertent activation in the event of a power surge (see Section B, Chapter 4446 for 'Unplanned Power Surges and How to Negotiate with Them'). To minimise threat to one's crew and property it is essential for the head pilot of a TARDIS to implement proper safety measures, listed as follows.

"No. 1. In order to avoid unplanned cellular transmutation or embarrassing premature regeneration (refer to Appendix, Line 4e+7 for further guidance), do not store the Chameleon Arch within a one-mile vicinity of fusion calibrators, plasma re-inverters, or any hair dryer with a wattage exceeding…"

Of course, being a manual of Gallifreyan origin, this goes on in a way so dull and egregiously longwinded that by number three on the list, most head pilots have dependably lost interest and skimmed their way to the much more intriguing subsection 'How To Operate' where the functions of pokey buttons and flippy switches and cool-looking twiddly bits are detailed. It should come as a truly disturbing revelation that even these irresponsible pilots (who attained only the barest possible understanding of the chameleon arch, and frequently lost a regeneration or two in doing so) were still far more qualified to handle the device than the head pilot of the last remaining TARDIS in the universe.

Shortly after stumbling upon the dust-coated instructions that belonged to his Type 40 – rather than opt to read it by the fire over a cup of tea as any normal, sane intellectual might – this particular pilot took exception to the very idea of anyone daring to tell him how to operate his TARDIS, and in a fit of astonishing (though consistent) immaturity, chucked the manual into the blazing maw of a supernova just down the way.

The pilot had never read it. Nor had he ever heard of any of the invaluable safety measures enumerated within. His vague, patchwork understanding of the Chameleon Arch was comprised of rumour, disreputable gossip concerning which High Council members had fetishes for turning into mice, as well as what little he'd retained of spottily attended, robustly flunked Academy courses.

But given his track record of deliberate incompetency, it can be safely assumed that even if he were privy to the appropriate safety measures, he still wouldn't have bothered to abide by them. And if pressed on the matter of wilfully endangering himself and his friends, would likely say something flippant and useless along the lines of, "More fun that way," or "What's life without a little peril?"

Thus, after its only usage, the chameleon arch installed in this final surviving TARDIS had been grumbled at, kicked a bit, and sniffed derisively; just before it was unceremoniously shoved up into the wiring of the ceiling, out of sight and entirely out of mind. Its gravity clamps stayed unclamped. Its time seal remained unsealed. Its surge-guards were left unengaged, and – perhaps most atrociously of all – its seatbelt was unfastened.

When this gross negligence is taken into consideration, the events of Saturday morning seem rather less shocking than Donna Noble found them.


"Spanner."

Donna pointedly raised her magazine higher, popping a crisp in her mouth and giving the pale, presumptuously upturned hand at her knee a dirty look.

The hand snapped at her as if it knew what she was doing and disapproved entirely. "Donna, the spanner," arrived the impatient request once more, punctuated with a beckoning flick of long fingers. "Hurry up."

Her glower drilled holes through the hand. She would have much preferred to drill a good hole or two in its owner. "I'm not your assistant, you know. Would it kill you to get something for yourself every now and then?"

There was a tired sigh. Recently she'd had to contend with a lot of sighing of the tired variety, and it was beginning to wear terribly on her.

"Just hand it here," sighed the Doctor. "You're closer than me."

The only proper seating in the room had long since been overtaken, the tatty yellow vinyl bench now inhabited by springs, cogs, frayed wires, and a mountain of loose, rusty bolts that looked like a tetanus infection waiting to happen – all which left Donna parked on what she'd deemed to be the least complicated-looking panel of the console. There was indeed a wide steel toolbox sitting beside her, housing the spanner in question. In reality it wasn't too much trouble to hand it down to him. But she felt like being contrary, so she narrowed her eyes at the hovering palm and said, "What's the magic word?"

"Oh, I dunno, Chiswick?"

Bristling, Donna snatched the spanner out the box. She aimed for the two long swathes of blue pinstripe trailing across the floor and lobbed the heavy tool at them, in the hopes the impact would be tremendously painful.

The Doctor's outstretched hand swung in a blur of inhuman dexterity: neatly plucking the spanner out the air before it could dent his shins.

"Thank you."

She didn't reply.

And such had been the frosty atmosphere in the TARDIS for a fortnight, ever since the unfortunate visit to Midnight.

Donna was all too aware that the Doctor was susceptible to dark, turbulent mood swings. A tangential mention of his homeworld, a question even slightly verging on personal, so much as a stray hair barrette on the kitchen table; it took barely anything to set him off, huffing and snapping and slamming doors for no reason like a teenage girl on her period. But those fleeting episodes of sourness didn't hold a candle to what she had experienced over the last two weeks.

His maddening enthusiasm, his fascination with every little thing there was to be fascinated by, his humour and recklessness and manic zeal for exploration – qualities which usually outlived even the foulest of strops – it was all gone. Everything positive that normally compensated for the odd mood swing had completely evaporated in the wake of his harrowing experience on that space bus.

All he had done, for fourteen whole days, was lay under the console and 'repair' things. In silence.

It was the mother of all sulks. In the past, even whilst he was in one of his moods, his gob still always had a mind of its own. He was an innately talkative bloke: physically incapable of lasting thirty minutes without rambling to himself or blurting out an idea for a trip or sharing a useless obscure factoid. Now the only time she heard him speak unprompted was when he asked her to fetch something out of that bloody toolbox.

She'd never once thought it possible that she would actually miss the sound of the Doctor's obnoxious marathon rambles, but as barmy as it was, she did. She missed him hovering far too closely at her shoulder and making withering remarks about her habit of reading rubbish tabloids, missed hearing him shout at his ship and complain to her about fluid links as if she had the faintest clue what he was going on about, missed telling him to shut up when he waffled for hours about tree planets and ice planets and vegan planets and all other sorts of nonsense places. And, in a way, she felt responsible for his decline into silence, having made the regrettable (albeit one-hundred percent justifiable) decision to lounge poolside and sip cocktails rather than accompany him on the bus.

So for the first week of his doom and gloom – knowing that he was working through the trauma of the incident on Midnight – Donna had made a genuine effort to stay calm and supportive. She'd kept a (mostly) level head and tried to be patient. But come the second week, the urge to shout sense into him became too great. Traumatised or not, his behaviour was properly absurd. He didn't eat, didn't sleep. She'd not even seen him get up to go to the loo once. He refused to discuss what'd happened on Midnight, even though it was painfully evident how much the ordeal had disturbed him. When she tried, loudly, to convince him at the very least to take better care of himself, the only response she ever received was an invariably tired, invariably sighed, "I'm fine, Donna."

She had no idea how to handle this stratum of despondence. Yelling – her usual recourse – had proven ineffective. And she was worried. The Doctor being quiet and withdrawn was like Donna suddenly becoming even-tempered and mastering subtlety; it was an unsettling notion no matter how you squared it. The man had the universe's most cartoonishly expressive face. It was a face meant to lift into big toothy grins, to go round and agog in bug-eyed bewilderment; to narrow into that thundery, professorial disapproval he was always giving her when she mistakenly inflicted some heinous insult upon an alien culture.

Seeing that wonderful, ridiculous face so drained and distant just felt wrong. It was impossible to decipher what emotions, if any, were clouding his mind. At least if he'd been engaging in his typical broody routine of snapping at her to leave him be and let him work, she'd have some clue that he was trying to cope. But he didn't snap. He didn't emote. He didn't do anything that didn't involve the console, the sonic, heavy sighing, and an occasional spanner. It was like the Doctor had abandoned her, and left in his wake an empty vessel that merely happened to look and sound and roll its eyes like him.

Nevertheless, Donna comforted herself with the thought that it couldn't go on forever. Fate would intervene. The Earth would be imperilled again at some point. Aliens seemed very insistent upon invading/harvesting/obliterating her home planet, after all. Once they made another attempt, then he'd have no choice but to emerge from under that console and make himself useful. And once he'd thrown himself back into the fray, into the action, he would remember how much he liked it, and finally come out of the nasty depression – or whatever the hell it was – he'd descended into.

She just needed to be patient. Something, she thought, had to eventually happen to change his mindset.

What she did not know was that this something was destined to occur in a mere hundred and eighteen seconds. And that it would change him in a way rather more literal than she was at all prepared for.

Both occupants of the ship, completely unaware of what would happen in approximately two minutes, had re-engaged in their own respective activities. The Doctor murmured softly to himself about dust, sniffed a little, and lapsed into more silence. Peeved that all he seemed to care about was the state of the bottom of the console – hardly even the most interesting side – Donna returned to the rigorous pastime of feigning indifference towards his wellbeing, flicking absently through her magazine as she tossed another crisp in her mouth and crunched on the snack.

It was at this single crucial moment that, unbeknownst to her, small, microscopic particles spewed from the surface of the poor crisp as soon as her teeth cracked into it. These particles hurtled down towards a remarkably delicate slot on the console at top speed, bearing the faintest hint of salt and grease and potato.

Nothing happened, obviously.

Then the Doctor's mutterings about dust finally came to fruition as he proceeded to drop his spanner and let out an enormous sneeze.

This jarring clang and achoo combination, erupting as it did from right under her perch, sent Donna leaping in surprise. Her bag of crisps leapt with her, crinkling as her fist tightened on it. Nearly the entire bag sloshed out onto her lap and onto the console: right down into that delicate slot.

The result was spectacular.

A wordless bellow that put the sneeze to shame issued from the console as a shower of red-hot sparks spat down onto its occupant. Limbs scrabbled in shock, and the Doctor rushed to sit – only to brain himself on the underbelly of the smoking console. He went tumbling right back down with an incoherent yell, ending up sprawled on his side, looking utterly besieged: like someone'd thrown firecrackers at a sleeping cat. "What?" he spluttered, eyes threatening to bulge right out his head. "What?"

Reflexively, Donna almost started to point and laugh. Then a column of scalding smoke surged out the top of the console, interrupting her mirth, scorching her shirt and sending her flying off the controls with an affronted squeak. A larger, even angrier collection of sparks spewed from her abandoned perch. Overhead a klaxon began to scream.

Something that looked quite important exploded.

To Donna, the next few moments melded into a blurry montage of madness. The Doctor muttered something furious under his breath and launched to his feet, shoving past her and ducking around the fire to throw himself at the controls, urgently flipping levers and unplugging things. The TARDIS made a sickly noise and dimmed with smoke at alarming speed, jostling the whole room around, seemingly determined to throw its passengers at the floor and break a bone or two for good measure. Heat was billowing, sparks sailing, tendrils of white flame lashing out the seams of the console. Two new alarms wailed in discordant harmony with the first, fighting tooth and nail to out-screech the ambient destruction around them: rubble crunching, walls rattling, glass cracking.

And then all of a sudden, surrounded by all that frightening, frantic chaos – the Doctor froze.

"You've dribbled crisps in the helmic regulator!"

It was, Donna realised with immense satisfaction, the most emotive he'd been since Midnight.

"Well, sorry," she offered, not feeling very sorry in the slightest, trying not to be pleased at the tight anger he was so clearly trying to keep off his face. "Didn't mean to. And it's your fault I spilled them, anyway. Who in the world sneezes like that?"

"What have I told you," he shouted, his voice rising to eclipse all three of the klaxons as he hurled the empty, incriminating greasy packet at the floor, "about eating in the console room?"

She was about to retort that he'd once lectured her for having a perfectly respectable cup of ice cream near his precious console – nothing at all had been said about crisps, so she was technically innocent, thank you very much – but before she could, the TARDIS gave a furiously violent quake, and finally succeeded in its mission to lob both its inhabitants to the floor.

A floor which, Donna couldn't help but notice as she laid flat on it, was beginning to tilt the wrong way.

"The gravitational circuits are failing!" The Doctor struggled to get back to the controls. "Hold onto something!" he shouted over his shoulder.

This seemed like a reasonable course of action, so she hastily grabbed the nearby railing. The Time Lord across the room was a frenzied blur, clutching the coral edge of the console as he twisted dials and jabbed buttons in a fruitless bid to control his vehicle. The floor lurched entirely sideways. Donna yelped as her feet slipped off the grating, knuckles turning white, legs dangling helplessly. She found herself staring across the room at a messy tangle of black looping wires. It took her a moment to realise, with belated alarm, that it was exactly what the ceiling looked like.

Metal stretched and screeched and rolled. The Doctor's inflection grew progressively more colourful-sounding. One red Converse was planted up on the console and braced against the handbrake, a pinstriped arm hugged around the Time Rotor as his other leg flailed for purchase. He was beginning to slip. She closed her eyes and clung to the railing for dear life.

The room somersaulted.

It all seemed like somewhat of an overreaction to crisps, in Donna's opinion.

She lost her grip and fell, screaming. The junk on the bench seat clattered off and fell with her. Even the Doctor's long coat fell, slipping from its home thrown over a coral strut and billowing out like an empty cape as it sank downward. Unlike the other objects in plunging transit, however, Donna's landing was cushioned unexpectedly: the fall broken by an unidentified cold and bony object.

"Ow!" it wheezed. "Donna!"

"What happened?" she demanded, scrambling off lanky alien into the hard rubber blanket of wires. She sat up and looked around anxiously – finding the room plunged into a vast, abrupt darkness, the Time Rotor glowing a soft and sickly aqua into dense shadow.

"The gravity failed." He sounded reasonably upset about it, so Donna made the educated guess that this wasn't a good thing. "High-voltage power surge must have short-circuited the mainframe, caused an automatic shutdown. The TARDIS's internal dimensions destabilised. Without her own to stay buoyant, she must have been dragged to the nearest centre of gravity."

"Which is?"

"A planet, odds are."

"Which one?"

"Well, let me just have a look at the monitor." His eyes widened comically and lifted upwards to where the console now resided. "Oh, wait."

She glared and gave his bicep a hard swat – setting him yawping and nursing it like he'd taken a bullet instead of a human palm. "What was that for?!" he shouted.

"I said I was sorry. Now: are we stuck up here?" She craned her neck to make out the console. "Or down here, whichever?"

"Yeah, just a bit, Donna. The door's several metres above your head, in case you haven't noticed." He probed gingerly at his arm once more, winced, let out a mighty sigh, then flopped back into the wires and clapped a frustrated hand over his eyes. "Crisps," he huffed. "Unbelievable. Tell them not to wander off, tell them not to talk to strangers, tell them not to eat in the console room – and what happens? I don't know why I even bother, I don't."

She ignored the rant, squinting at him in the dark and frowning at the presence of a few unpleasant-looking injuries. There was a bruise swelling over his eyebrow as a consequence of head-butting the console, and enough dirty grey soot smeared across his skin to make him look like he'd narrowly escaped a coal mine. He sported the shiny raw graze of a burn on his jaw where the heat of the flaring console had singed him, and had taken the brunt of the broken glass as well, his face peppered in tiny, angry little cuts.

Donna felt rather contrite for hitting him then, and wanted to ask if he was all right; but something told her he wouldn't appreciate her sympathy just now. She sat back on her heels, glancing around once more.

That was when it caught her attention.

"Uhm," she said, a bit hesitantly. "Doctor."

"Hmm?" he grunted. "You planning on wrecking my TARDIS again?"

"No, there's a… well, whatever that thing right there is. Is it supposed to be fizzling like that?"

"Fizzling?" He peeked through his fingers, then dropped his hand all the way. "What's fizzling?" Frowning, he sat upright and turned around. Donna pointed a finger to direct his questioning gaze to the helmet-like device resting a few feet away.

Thin white veins of electricity were jolting along the domed metal cap. The current glitched and cracked, brilliant and disjointed, spitting up spindly curls of steam. And right then – conveniently, almost as if it'd just been waiting to get their attention – the lightning began to snake up the heavy-duty cord that branched from the top of the helmet. Letting out a very soft, very deadly-sounding hiss.

The Doctor stiffened.

Before Donna could form the words to ask him what'd gone wrong now, one hundred and sixty odd pounds of Time Lord bowled her over.

Her eyes flew wide in shock, and she instantly, furiously struggled, indignant. "Oi! Off!" She felt his bony knees clamp tight on either side of her hips, his chest pressing into her back as he hunched over her. "Get off me, Dumbo!"

The explosion, as explosions went, was positively deafening.