Donna skidded to a graceless halt in the Cloister Room, and almost slammed into the Doctor's back. Recovering with commendable speed, she looked around and then up, and lost her breath once more.
The room was lit by a massive crystal dome containing millions of intricate triangular facets, which let onto a twilit sky dominated by a stately, turning galaxy. As Donna stared at it, slack of jaw, she saw a supernova twinkle briefly in one of the outer arms before it died away with shocking speed.
She finally dragged her gaze down and took in the rest of the scenery; beneath the dome were ranks of sharp Gothic arches picked out in wrought iron, each containing its own deep puddle of shadow, and in the middle of the room there was the Cloister Bell.
It was heavy and primeval, a study in decrepitude, with one evil scar running down its rusted black flank and a deep gouge in the rim. This debauched grandeur was offset by the fact that this gnarled monster hung, quite motionless, in an intricate cat's cradle of silver chain that looked – set against the weight of the bell – to be as fine as cobweb.
The tolling, Donna was beginning to realise, was approaching tolerable in here, and she wondered how that could be so when they were standing less than a dozen feet away from the bell itself. She sidled across the floor, heels dragging, and reached out tentatively.
Laying one hand on the great curve of the bell sent a shudder up her arm, into her brain and back down her spine on a hairpin bed. The iron was vibrating so gently that she had to press her fingertips hard up against it in order to feel it at all. It was far too soft a movement to be producing the sonorous peals she was hearing.
While Donna had been otherwise preoccupied, the Doctor had stepped up beside her. He was frowning fiercely.
"Something's not quite right here," he muttered, then bent at the waist and poked his head up inside the bell. After a few seconds, perturbed by the fact that he had not resurfaced, Donna joined him.
There were two kittens in there. One had all four paws wrapped around the clapper and was swinging it to and fro, bouncing off the inner curve of the bell with every sign of enjoyment writ large across its pinched, cross-eyed little face. The other, which looked to be egging its companion on, was perched on the narrow inner lip of the bell. It glanced over at its audience, and set to washing itself with a surprisingly credible air of innocence. The Doctor sighed heavily, reached out and plucked them both up.
He then straightened up and paused visibly.
Donna stared as the Doctor weighed a kitten in each hand, preoccupied, almost as if he were trying to decide between two bunches of bananas in the supermarket. He narrowed his eyes at one and lifted the other; they opened little pink mouths and mewed at him in perfect sync. She watched a smile dawn on his features.
"Of course," he murmured, then rounded on Donna and held the animals out triumphantly, the smile transmuting all at once into a wild grin.
"One of them's just widdled down your sleeve," she told him. He apparently ignored this.
"Look at them!" he insisted. Donna subdued her irritation and studied the kittens. Both were patterned with black and white blobs, and had one endearing wonky ear apiece, although one kitten's was on the left side and the other's was on the right. She couldn't see anything out of the ordinary, and scowled up at the Doctor in an effort to convey this.
"It's the same kitten," he explained, "except they're mirror images. What do you know about quantum theory?"
Donna snapped.
"Strangely enough," she began, pouring sarcasm like hot custard over each syllable, "not a lot. I think I was ill the day we did quantum theory in bleedin' primary school! Now what are you waffling on about, please?"
The Doctor, by way of response, merely handed her a kitten. It did not escape her notice that it was the damp one.
"Think proton and antiproton," he said, firmly. "When those two particles meet, they both vanish. Watch carefully," he added, and before Donna could speak, he had moved his kitten up alongside hers so that they touched. There was a startling flash of pure white light, and when her eyes had cleared themselves of the more bizarre after-images, she looked down to see that both animals had completely disappeared.
"Cat and anticat!" said the Doctor, gleefully.
The Doctor hared down the corridor in pursuit of a small pack of ginger cats. They skidded around the corner, tails held aloft like quivering flagpoles, but when he turned the corner himself, they were gone.
Behind him, a bright flash erupted from a doorway. He half turned.
"Got one?" he called, irritably.
"No," came Donna's slightly muffled reply. "I'm taking a picture."
"Why?"
"You should see what this lot are doing," said Donna, cryptically.
"Just get on with it, please," said the Doctor, seizing a huge breath. When he looked back, the cats were watching him carefully. He released the breath, slowly and gently, and made a sudden grab for them.
This turned out to be both a very good and a very bad idea. He managed to secure a hold on two of the cats; however, while he had been doing this, the others had decided to launch a counter-offensive. As the Doctor lifted his captives, he became aware of an odd sensation around the toes.
He looked down to see several more cats gnawing on his sneakers. Three were going straight for the shoes, while a fourth had seized upon a stray shoelace as the grand prize and was tugging ferociously at it as if it were a recalcitrant worm.
Snarling, the Doctor dispatched the two he was holding and then bent double like a pinstriped flamingo, grabbing for his attackers, which promptly scattered. He set off after them – and would have made a fine job of it were it not for the trailing shoelace. By the time he'd scrambled to his feet and made an attempt to straighten out his nose, they were gone.
Donna, meanwhile, pocketed her camera and picked up two more cats from the pile in front of her. They regarded her incuriously and stuck out twin pink tongues. Satisfied by this, she brought them together and squeezed her eyes shut as the actinic flare consumed them.
When her vision cleared, she glanced down. One cat remained, and it was curled up at her feet, sides rising and falling infinitesimally, tail curled about and tucked neatly beneath its soft pink nose.
Donna sighed and turned her head, looking for its opposite number, but they were quite alone in the room. She looked back down again; the cat continued to sleep, and one ear vibrated ever so slightly in the midst of a dream.
She knelt down and studied the animal at closer quarters, and it was only now that a sense of familiarity began to creep over her. She stretched out a hand and ran idle fingertips through the dense tabby and white fur, running them up through the silky hairs until she located something she had not so far found on any of the other cats.
It was a collar. Pushing the fur aside, Donna could see it was a purple velvet collar with little fish embroidered on it in silver thread. The sense of familiarity grew heavier and more involved, and was now joined by a distant memory, so vague that she could only link it to this collar.
Her fingers strayed further; the cat shifted in its slumber, but otherwise reacted no further than to squeeze its eyes shut even tighter. At last, Donna found the small brass disc attached to the collar, gripped it delicate between finger and thumb and turned it around so she could read the engraving.
She read it two more times, just to be sure.
Her puzzled half smile, which had been fading steadily, vanished altogether.
Then she gathered the snoozing cat into her arms and set off in search of the Doctor.
