Eventually, they manhandled the gently smiling drunk into a sitting position against the fountain. Donna stood back, looked at her palms in horror and then turned and wiped them on the Doctor's sleeve.

"Hey! Do you mind?" he yelped, shying away.

"Well, you've got it all over you anyway," said Donna, not unreasonably. "What's a bit more?"

The Doctor couldn't come up with an adequate retort to this, so he paced around the fountain and watched the conflagration carefully. A fresh platoon of golems thundered through the square, each one carrying two enormous buckets of water. Several had obviously come straight from their jobs; he spotted one in the blue and gold flashing of the Post Office, and another dressed as a clown; which, mused the Doctor, must have made for some rather bizarre children's parties lately.

There was also one with a live chicken strapped to its arm. He struggled not to speculate.

Once the phalanx had crashed past, he peered across the square at the collected members of the Night Watch, clustered on a corner well out of the way of the bucket chain. Angua was sitting well back on her haunches and sniffing vociferously at the air. The Doctor decided that this did not bode well, especially when the smoke started to clear. He turned and scuttled back to Donna.

"I suggest a tactical withdrawal," he said, softly, "before Ankh-Morpork's finest come looking for their missing detainees."

Donna, who had been studying the snoozing man, jerked her gaze up.

"What?" she said. "We can't just leave him here like this!"

"What do you suggest we do," asked the Doctor, decorating each word with sarcasm, "leave a note saying, 'Here's your drunk back, thanks for the lend'?"

Donna's eyebrows dropped.

"I just meant that we should let them know we're all okay," she hissed back.

Another lot of golems thumped and sloshed past the fountain. The Doctor ducked, but not before noticing that one of them was carrying an inordinately large cucumber. Either it worked in the vegetable market, or...he stamped so heavily on the ensuing thought that he stubbed a mental toe. Donna, meanwhile, was still scowling at him.

"They'll know that when they don't find three crispy fried people in the cells, all right?" said the Doctor, now beyond irritated and into exasperated. "I love your sense of civic duty, Donna. I really, honestly do. But they do have other Watch houses with other cells."

"Fwahaaaaaammmm," muttered the little man, mid-snore.

"You stay out of this," said the Doctor, absently. "Anyway, coming?"

Donna shrugged, and traipsed after him.

They were at the head of the bridge when she grabbed the Doctor's arm.

"Where's Arthur?" she asked, concerned, looking back the way they'd come.

"I thought he was with you?"

"He was," said Donna. "I lost him by the front desk, and then things got a bit complicated. I thought he'd followed you."

The Doctor shrugged.

"Believe me, he can take care of himself," he said, and headed off down the bridge, shoulders hunched. Donna frowned at his back and planted her hands on her hips.

"We should make sure he's all right!" she shouted.

"He is," said the Doctor, without turning around. Donna trotted after him, suddenly angrier than she'd been in quite some time. Well, certainly within the last five minutes, anyway, she amended.

She caught up with the Doctor at the last statue, but he had already come to a grinding halt. Donna peered around his side to see what was going on.

Vimes was leaning up against the door of the TARDIS, arms folded, cigar stub tucked into the corner of his mouth. After a few seconds, he looked up at them as if he'd only just realised they were there, plucked the cigar, dropped it and ground it out beneath his boot heel.

"Evening," he said, conversationally, and fell silent again. The Doctor tried to see if Vimes was smiling, but that face gave nothing away. Vimes could make the average golem look like the Laughing Cavalier when he wanted to.

"Hello, Commander," he replied, trying to keep up in the non-committal stakes.

"Is this yours?" asked Vimes.

"Yes, it is,"

"Well, it's illegally parked," Vimes continued, "but here's what. I don't want to know who you two clowns are. I don't want to know what this or how you got it here. My Watch house is charcoal and considering that I have to be the one to explain to His Lordship how that happened, I think my life is complicated enough for one night.

"In fact," he went on, stepping away from the TARDIS and standing nose to nose with the Doctor, "all I do want to know is that you won't set one bloody foot in this city ever again."

The Doctor, quite mesmerised, hadn't drawn breath throughout this whole speech. Finally, he inhaled deeply, and grinned.

"I won't," he said, cheerfully. Only Donna could see that he had his fingers crossed behind his back; she snorted out a very soft laugh, which didn't seem to be entirely lost on Vimes. However, he merely looked her up and down and said nothing.

"Off you go, then," he said, at length, and trudged off into the gloom without a backward glance. They watched him until he was out of sight.

As soon as the Doctor had closed the door behind them and started the engine, Donna pulled at a strand of her hair and sniffed it for a second.

"Ugh," she said, grimacing. "Bags I'm first in the shower."

"Oh no you don't," the Doctor retorted. "Me first."

"I stink of smoke!"

"I'm covered in sick!"

"Okay," said Donna, after a long, disgusted pause to examine his suit jacket. "You win."

Just then, she heard a familiar voice from somewhere close by.

"I cannae help recallin'," it said, lazily, "talk o' a kiss?"

Donna froze solid. For a moment, only her eyes were capable of any movement at all; they swivelled madly from side to side. Arthur was nowhere to be seen. Finally, as a dreadful, awful certainty seeped into her brain, she tilted her head back on muscles that seemed to squeak.

The gnome leapt.