'What's happening!?' Donna shouted again, her voice sounding small and frightened under the torrential creaks and aches of the time ship's engines. 'What the hell did you do, you dumbo!?'

The TARDIS lurched once more; the wild-eyed figure before her toppled backward against the console. 'Me!? I didn't do anything!' It sounded affronted and then went somewhat green in the face as the floor racketed and bumbled. 'Blimey, I think I'm gonna be sick.'

You're going to be sick? Donna thought as her stomach also clenched, not just because of the pseudo rollercoaster ride, but also because of what had become of the man before her. To think she hadn't even noticed when something had come and taken over the Doctor. Her best friend.

It had taken so long—so many months of research, travel, and subterfuge—for her to find him again. She'd embarrassed herself in all manner of speaking trying to hunt down what she'd thought to be alien activity on Earth; the only avenue from which to find him again. That taxi driver, the disappearing bees, and even her own mother on one occasion (maybe even twice). It had started to become a blur as she grew numb to the shouting over time. As well as the cursing, the bans, the throwing's out, and the promises of karmic retribution. But still, she'd kept searching for him.

And searching… and searching...

Towards the end of it all, trapped in that Adipose Industries toilet—while that shrewd nanny with the professional specks had her goons knock open stall door after door, looking for that reporter—Donna had really, truly begun to wonder if it was all worth anything.

Don't be stupid—of course, it is, she'd told herself and held her breath.

And it was. It so was. Every night aboard the TARDIS since she'd had to pinch herself to ensure that she hadn't dreamt it all up—that she and that skinny alien man were actually out saving the universe in a funny, blue police box. Pompeii, then the Odd Sphere, and London again and again. They'd helped so many people and Donna knew everything was going to be all right in the end because they had each other. No matter what happened they were a team. A unit. Inseparable. The Doctor and Donna. Nothing could come between them. Except—

She couldn't even look at him now. This… thing that was tottering about with the Doctor's face and body, wearing them as easily as a fur coat in December; who treated Donna like a stranger one minute and then someone he knew utterly and unquenchably the next. As if they'd been old friends just having a laugh. But Donna didn't know him. She knew that for certain. This strange man (was it even a man?) was not the Doctor and he wasn't her friend and the moment she saw fit she'd throw him out the TARDIS doors, back to wherever he came from!

But then… that would harm the Doctor, wouldn't it? If it was still his body, of course. Whatever was impersonating him could be a shape-changer or some sort of organism that'd got inside the Doctor's brain like in the movies. He could be in a lot of pain right now, trapped inside his own mind while something else puppeteered him. Maybe that bit of familiarity Donna sensed was really the Doctor trying to break through the manipulation—to communicate with her. Or maybe the creature was somehow reading his dormant mind, using his thoughts to construct a Doctor-like persona to last it till it was ready to eat her.

Another hard vibration hit the floor. Donna gasped, having nearly forgotten the arduous behaviour of the TARDIS after a momentary reprieve from the tantrum. One wrong step sent her spiralling into the figure's arms.

'Steady,' she heard it say, punctuated by a rasp from the time rotor—the crawl it took to regain a foothold on the time ship's irate movements. A chill went up her spine as it moved to wrap a protective arm around her. Despite everything that had led up to this moment, Donna decided to let it till the shaking stopped. Seconds felt like minutes. Then hours. Finally, something inside the TARDIS croaked. She felt her ears pop as the rotor suddenly seized, leaving a deafening silence in its wake. When the ground finally stabilised, Donna found her legs were still shaking.

Its grip on her eventually softened and she steadily pulled away, trying to gauge its next move. The figure didn't seem to notice, its attention drawn to the hexagons that lined the cavernous interior of the TARDIS just as their blue-green light shifted, taking on a mauve hue.

'What was that? Did we crash into something or…?' came the Doctor's familiar voice, intoned with that foreign Welsh lilt.

Why? Donna began to consider for the second time that day, did this creature sound like it was from Wales? The Doctor explained once that the TARDIS translated alien languages into English with easier-to-understand accents (however much sense that really made). Perhaps that was the case with this one, but after a time Donna had begun to have a sense of when the TARDIS was actively working its linguistic magic on her. Just a little tease in her ear; a nip of the original language that she could only sense when she concentrated enough. Concentrating now, she couldn't feel that tease as he kept on speaking. This meant he had to be speaking English and could in fact be Welsh. Did that mean the creature was Earthly in origin? Or something commandeered from the future after humans had taken over galaxies. Maybe it was actually a computer that—

'DONNA!'

At the sound of her name, Donna jumped and opened her eyes to find the Doctor's freckle-specked face very near and scrunched up with concern. 'Are you all right, Donna?' the thing in control of him repeated for perhaps the third time.

'Yeah. Fine,' she heard herself say. It couldn't be any further from the truth. Donna was prepared to say more, getting a whole speech about the rules regarding body snatching and face stealing and something to do with that Shadow Proclamation ready in her head, but then a short trill of sound caught the creature's attention and her window of opportunity passed.

Regarding the sound, Donna wanted to say 'It always does that,' so the creature wouldn't go poking around the console, but it was clear in her mind this wasn't the case when she saw the pulsing red diode— hidden between two globes and an oblong wheel—that the Doctor has once told her was an emergency signal.

They both stared at it for a good long while, before the creature stepped over to the console, reaching towards the diode, and surreptitiously flicking the accompanying switch. The diode buzzed and turned green, the console monitor switching from the scrolling alien text to a view of the cosmos and—

The creature's jaw dropped. 'Oh my God,' it said, breathlessly. 'That's a space station—a real, proper space station!'

Indeed, it was. Sitting picturesquely among the stars was a ginormous, thick white, metal pole surrounded by several wide, doughnut-shaped rings each attached to the centre piece by a series of tubes set equidistantly apart from one another. At the top end of the pole was a disk shape resembling two cymbals being pressed together with an antenna sticking out. A green light emanated from one of the middle rings along the pole, flicking in and out of sight.

The longer Donna stared at it, the more something unusual about the station became apparent: it was growing.

No, she quickly realised, not growing.

'OH!' exclaimed the creature, causing Donna to nearly jump out of her skin. 'The light! I bet it's a tractor beam of some sort pulling the TARDIS in. Must be what gave us a good shove and caused her to destabilize.'

'And do you think that's a good thing?' Donna's words snapped at him like the very angry claws of a crab. She'd finally found her voice now that she could see the imminent danger and didn't appreciate how utterly pleased the creature sounded by it. It was only after she'd shouted, she figured it was the wrong move to make as now the creature in charge of the Doctor's body had been given a reason to bite back.

'She'd shouted at me, so I decided to eat her', it would say. 'Delicious little human, too. Tasted like chicken.'

She waited for this and instead, much to her surprise, received an apology.

'Sorry,' it said heavily, almost as if it was just as terrified of what it saw as she. 'Just got caught up in the moment, s'all.'

With that emission of guilt, Donna began to realise she had much more control over the situation than she thought reasonable. She considered screaming, shouting, and even raving, but after nearly six months of travel with the Doctor, she had learned to be slightly more diplomatic in her approaches to alien life or those similar (like Nerys).

Donna began with a 'that's all right,' and when that went over well, she couldn't contain her emotions much longer. 'Now that you've gotten it out of your system, though, do you mind telling me who the bleeding hell you are? What have you done to the Doctor? Some sort of body snatching or shape-shifting or cloning or something? If I find out you've hurt him…'

The creature brought up its hands placatingly, backing up into the jump seat as Donna poked at his chest, suddenly seeming a lot less threatening as he prattled out, 'Oi! Okay, I get it! Look, my name is August! I don't know where the Doctor's gone; I don't even know what I'm doing here, but I can promise I don't mean you any harm!'

Donna's gaze narrowed sceptically. 'That's a very human name.'

'Well, I am human,' this August said matter-of-factly. He then paused and begrudgingly added, 'Well, normally.'

'From Earth?'

'Yes.'

'Wales?'

'Actually, I was born in London… Mam's from Wrexham, though.'

Donna rolled her eyes, finding a part of her was actually disappointed she wasn't telling off a slug-brain-snatching creature from Mars and instead was berating a fellow Londoner who seemed a trite cowardess. Then again, Donna had that effect on men. Then again, he could be lying, but Donna knew a thing or two about liars ever since Lance. Still…

'And you know the Doctor? You know about the TARDIS? You know me?' she asked.

August nodded his head side-to-side. 'Sort of…'

'What do you mean "sort-of"?'

'It's complicated.'

Donna huffed. 'Then uncomplicate it!'

He huffed, rolling his eyes in what most would figure to be impatience, but Donna had the slightest inclination of sadness and fear in his voice as he spoke. 'It's not that simple, Donna. And I really don't think we have the time…'

This time Donna took a deep breath to calm herself. This back-and-forth was getting them nowhere and the hairs on the back of her neck were beginning to stand on end as if they could sense the closeness of the space station as it pulled them nearer. He must have been feeling the same for August's eyes kept darting to the console monitor beside him, but she wouldn't have his excuses. Intentional or not, he'd stolen her best friend's face. She wasn't going to let that slide and if he had some sort of explanation to offer, no matter how long it would take or how uncomfortable it made him to tell, she was going to get the answers she deserved.

Donna sat down in the jump seat. She crossed her legs and folded her arms. She gave August and steely stare with her chin raised. 'Better start talking, then.'

The Lieutenant sighed as she looked over her station. Her name—not that the commander ever bothered to learn it—was Jeana Darke and she hated her job. Oh, she could sound all official and nice for his sir, but by mid-evening she'd much rather be in her quarters, taking a nap or reading up on the latest alien-bio blogs. Instead, she was stuck on the bridge watching that funny blue box draw closer and closer to bay four through her station screen.

Jeana's pouty lips scrunched up in distaste. The commander seemed to think the box was something to worry about, but she couldn't see why. It was just a plain old box—probably tossed out the back of a cargo ship for being so useless. What did it matter what was written on it? The scans hadn't even picked up any life signs aboard.

'I was supposed to be only on the midday shift, ya know,' she told the box. 'But because of you I have to stay up here for another half-hour, then I've got to do an inspection and fill out all that paperwork! And for what? An empty piece of space junk!'

As soon as the words left her mouth an alert popped up on her screen. 'That can't be right,' she muttered, flicking through the page of data. 'Why can't you be steady?' Jeana frowned as she trailed off, tapping her earpiece. 'Yes, hello, connect me to cargo bay ten, please… Right. No connection? Typical. Send me to Feric Burkinn's personal link.' She tapped her fingernails against her station as she waited. 'Feric? You still in cargo bay ten? No? Weird, cos I'm getting fluctuating life sign readings. There's only supposed to be eight, but the system keeps wanting to say nine. Can you check it out?' At the response she received, Jeana rolled her eyes, 'Right, then I'll just do it myself. Better than being stuck up here for the next half hour. Ta.'

Jeana hung up with a smarmy smile on her face, never to know how good her life could have been if she'd just stayed on the bridge.

August was pacing. He'd been doing so for the last several minutes, one hand propping up his elbow as the other picked at his lip. The space station took up all of the console monitor's screen now. The sweat beading down the side of Donna's face was the only indication of her concern which she quickly wiped away the moment August finally turned to face her.

'Um. Okay. So, to preface: my name is August. I work at this museum in Dalery which is a small town just southwest of Sutton. I'm not, like, a tour guide or anything. I just work at the gift shop, so I'm really nothing special. I mean, I've barely even gotten my A-level, so you know—ta to that, but the point is today. Today was special cos I went to this convention with my mates and we did the whole cosplay thing and it was brilliant, but then the whole thing starts to go fuzzy, and the next thing I know I'm waking up in the TARDIS of all places and you're here and I'm… I'm…' He couldn't get the words out and instead gestured to the skinny body of the Doctor he possessed before running a hand through the spiky locks of hair atop the Doctor's head. The result left him looking like he'd just stuck his fingers into an electrical socket.

'You realise none of that explains how you know the Doctor. Or about our travels,' said Donna. His needless ability to work around the point was infuriating her. 'It's a simple enough question! I'm not asking for a life story!'

'I'm sorry, I know. I'm just—' He sighed, seeming agitated with himself and the lack of clarity he could give to his words. 'The convention I mentioned. It's important cos it had— I mean, I was— There was this—' Seeming fed up with himself, August clapped his hands together and brought his pointer fingers up to his lip. Then, after a deep breath, said in the most deadly serious tone, 'Doctor Who.'

Donna stared. 'What?'

His cheeks turned bright red and, alas, August began pacing again, a look on his face like he was trying to explain weird hobbies to Mother. 'Doctor Who,' he repeated with more confidence. 'It's a show on the telly—a show called Doctor Who. It's all about the Doctor's life. It's how I know the Doctor.'

There was a long moment of silence between them as he waited for a reaction from Donna. Eventually, she blinked, leaning forward in the jump seat.

'Are you having me on?'

'No, I—'

'What do you take me for? An idiot? A show on the telly? What kind of—'

'Hold on. Holdonholdonholdon!' August interrupted, holding up two fingers. Once he was satisfied Donna wasn't going to interrupt again, he took another deep breath and started speaking very quickly. 'Christmas day, just last year, you were getting married to that Lance bloke when you suddenly found yourself in the TARDIS with the Doctor because of the Huon particles Lance had been putting in your coffee for the Racnoss Queen. You were attacked by robot Santas and Christmas ornaments. The Thames was drained because all the water went into a big hole at the bottom of the H.C. Clement's building which was filled with baby Racnoss.' He was smiling now, looking at Donna expectantly, as if that was all the proof she needed to deem him sane. 'There's no way I could know all that, right?' he asked her softly. 'It's because where I come from it's all a television show! I even watched you and the Doctor parading around Pompeii on BBC One!'

Donna maintained her side-eye glare. 'You've got the Doctor's body. How do I know you haven't got his memories as well?'

August blanched. 'That's… true,' he murmured, but just as quickly as his smile had faded it returned and he began bouncing up and down, once again holding up those fingers. 'Ah! Ah! Okay, but you didn't tell the Doctor about when you hid in the toilet at Adipose Industries, right? I'm right, right?'

Donna gave him the stink eye.

August continued, unabashed. 'That Foster woman was looking for you, but she found the reporter instead. You'd been on your phone with your mum before that. She was asking where you were so she could get the car and then when she asked why you were whispering you told her you'd gone to church!'

He looked like a maniac with his big wide eyes, heavy breathing, and clenched teeth, but he was also right. Donna hadn't told the Doctor about her stint in the bathroom at Adipose Industries and would have never mentioned an embarrassing phone call with her mother to him. Ever.

'You know how stalkerish you sound? Look, I'll give you that one. But—' she held up her hand before he could get any ideas— 'a television programme? Really? I think I would know if one about the Doctor's life existed! Especially if I was part of it!'

'Parallel Universe!' came his quick reply.

'Oh, you have an answer for everything don't you!' Donna sneered.

August's brow furrowed. He opened his mouth for another retort when an electronic, feminine voice interrupted him. 'Docking Bay Four door opening. Please wait.'

'Who was that?' asked Donna, finding her shoulders very tense all-of-the-sudden.

'Artificial voice,' said August, turning back around to face the console monitor. 'I think we've arrived at the space station.'

Donna came up beside him. The monitor screen showed two, large metal doors slowly pulling apart to reveal a cluttered hanger bay big enough to fit two large aeroplanes. That green flickering light August had called out before originated from somewhere in the wall straight ahead of them. The tractor beam, Donna realised. And it was pulling them in.

'What do we do?' she asked August.

'I dunno,' he muttered back, biting his lip. 'Normally the Doctor—'

'Well, he's not here, is he?! Instead, I'm stuck with you!' Donna snapped, overwhelmed with all the emotions she'd been trying so hard to bury. She thought, maybe, just quite possibly, she could handle being the one in charge. But she was already at a loss for what to do and whom to trust, feeling very small and very scared and oh so very useless.

'Vehicle occupants,' that electronic voice called, 'please vacate your vessel or be terminated.'

'Oh, just great!' cried Donna. 'Did you hear that? They're going to bloomin' terminate us! What are we supposed to do? What can I—'

'Donna! Donna!' August grabbed hold of Donna's shoulders. She let him, although once again she didn't know why. She felt like punching him in the face but thought that might be counterproductive. 'Look, I know you're confused. So am I. I'm in a completely different body, a completely different universe, and there's a…' he motioned to the TARDIS doors with a flailing hand, 'a flippin huge space station that just pulled us in with a tractor beam.'

'Are you always this good at pep talks?'

He strangely laughed at Donna's comment, cruelly utilising the Doctor's big, sad, puppy dog-like eyes as he looked at her. 'Can… Can you just trust me? For now? Cos whoever's out there is going to come for us. No one picks up the TARDIS without good reason. They might not be able to get in, but if we take that chance and something goes wrong… I couldn't live with myself if you got hurt.' He swallowed hard and Donna felt a sudden wave of sympathy wash over her at the spark of admiration that lit his eyes. 'I promise we can talk about all this weirdness after. I'll explain everything I can. We can try to make sense of it all and find out what's happened to the Doctor, but right now I think it's best we don't let ourselves get—well—terminated.'

Donna took a deep breath. Everything was so confusing and complicated. She didn't know what to think, but there was a strange sense of earnestness about August that gave her the feeling she could trust him. He might be completely mad—with his talk of parallel universes and television shows about her life— but then again, she did travel with a skinny alien in a time travelling police box, so anything was possible.

What would the Doctor do? Donna considered. Then like a flick of a switch, her clouded expression tightened into firm resolve.