Ben Aaronovitch - Rivers of London

London was also shrinking. Gaps were opening in the buildings on either side. I could see green pastures with hayricks and herds of cows. Things were losing focus around me. Ahead the River Fleet appeared, and suddenly I was dipping down to cross a stone bridge, while on the other side of the valley there were walls — the ancient walls of London. I only just made it through Ludgate before the actual gates had grown back and barred my way. The old cathedral was long gone; we’d missed the Anglo-Saxons and what modern go-ahead historians like to call the sub-Roman period, and paganism was back in fashion.

If I’d been thinking about it, I probably should have stopped and had a good look around, answered a few important questions about life in Londinium, but I didn’t because that’s when I closed the last couple of metres on Mr Punch and rugby-tackled the dead fucker to the ground.

‘Mr Punch,’ I said. ‘You’re nicked.’

‘Bastard,’ he said. ‘Black Irish bastard dog.’

‘You’re not making yourself any friends here, Punch,’ I said. I got him back on his feet with both his arms jacked far enough up behind his back that he wasn’t going anywhere without at least a broken elbow.

He stopped squirming and turned his head until he could watch me with one eye. ‘So you got me, copper,’ he said. ‘What are you going to do with me now?’

It was a good question, and a sudden savage pain in the hollow of my throat reminded me that I was running out of time.

‘Let’s see what the hanging magistrate makes of you,’ I said.

‘De Veil?’ asked Mr Punch. ‘Yes please, I’m sure he’ll be delicious.’

Revenant, spirit of riot and rebellion, I thought, you idiot. He eats ghosts. I needed something stronger. Brock had written that the genii locorum , the gods and spirits of place, were stronger than ghosts. Was there a god of justice? And where would I find him — or maybe her? Then I remembered: a statue of a woman stands atop the dome of the Old Bailey. In one hand she holds a sword and a set of scales. I didn’t know if there was a goddess of justice or not, but I was willing to bet big money that Mr Punch would know.

‘Why don’t we go and ask the nice lady of the Old Bailey?’ I suggested.

He tensed, and I knew I’d bet right. He struggled again and slammed his head back, aiming for my chin, but that isn’t exactly a new one for a policeman, so I had my head back safely out of reach.

‘You’re going up the steps this time,’ I said.

Mr Punch went limp, defeated I thought, but then he began to shake in my grip. At first I thought he was crying, and then I realised it was laughter. ‘You’re going to find that a bit difficult,’ he said. ‘You seem to have run out of city.’

I looked around and saw that he was right. We’d gone back too far, and now there was nothing left of London but huts and the wooden stake rampart of the Roman camp to the north. There was no stonework at all, nothing but the new-cut smell of oak planking and hot pitch. Only one thing stood complete — the bridge. It was less than a hundred metres away and constructed of square-cut timbers. It looked more like a fishing pier that had got ideas above its station and crossed the river in a fit of exuberance.

I could see a crowd halfway across, sunlight flashing off the brass fittings of a file of legionnaires standing at attention. Beyond them a cluster of civilians in togas chalked to a blinding white for a special occasion and watching a couple of dozen men, women and children in barbaric trousers and brass torcs.

Suddenly I understood what it was Mama Thames had been trying to tell me.

I think Mr Punch understood as well, because he fought me all the way as I dragged him across the bridge and in front of the toga-clad officials. These were more echoes from the past, memories trapped in the fabric of the city — they didn’t react when I threw Punch down before them. I was in Year Five when we did Roman history at school, so we didn’t learn a lot of dates but we did do plenty of group work on what it was like to live in Roman Britain. Which was why I could recognise the officiating priest by the purple-striped stole that covered his head. I could also recognise him by his face, although he looked a lot younger than he had when I’d seen him in the flesh. Plus he was clean-shaven and his black hair hung around his shoulders, but it was the same face that I had last seen propping up a fence at the source of the Thames. It was the spirit of the Old Man of the River as a young man.

Suddenly a great many things became clear to me.

‘Tiberius Claudius Verica,’ I called.

Like a man emerging from a daydream, the priest turned his eyes to me. When he saw me he broke into a delighted grin. ‘You must be my gift from the gods,’ he said.

‘Help me, Father Thames,’ I said.

Verica plucked a pilum from the hands of the nearest legionary — the soldier didn’t react — and handed it to me. I smelled freshly cut beech wood and wet iron. I knew what to do. I upended the heavy spear and hesitated. Mr Punch shrieked and bellowed in his strange, reedy high-pitched voice. ‘Isn’t it a pity about pretty pretty Lesley,’ he squealed. ‘Will you still love your pretty little Lesley when her face has fallen off?’

This is not a person, I told myself, and drove the pilum into Mr Punch’s chest. There was no blood, but I felt the shock as it pierced skin, muscle and finally the wooden planking of the bridge itself. The revenant spirit of riot and rebellion was pinned like a butterfly in its display case.

And people say modern education is a waste of time.

‘I asked the river to give us a sacrifice,’ said Tiberius Claudius Verica, ‘and a sacrifice was provided.’

‘I thought the Romans frowned on human sacrifice,’ I said.

Verica laughed. ‘The Romans haven’t arrived yet,’ he said.

I looked around. He was right, there was no trace of London — or the bridge. For a moment I hung suspended like a cartoon character, and then I fell into the river. The Thames was cold and as fresh as any mountain stream.

I came up feeling horribly wet and sticky. There was blood smeared over my chest and I’d wet myself at some point, probably when she’d bitten me. I felt drained and voided and numb. I wanted to curl up and pretend that nothing was real.

‘That,’ I said, ‘is never going to catch on as a tool for historical research.’

Somebody was retching but amazingly it wasn’t me. Molly was hunched over, her face turned away and hidden by her hair, vomiting blood onto her nice clean tiles. My blood, I thought, and climbed to my feet. I was light-headed but I wasn’t falling over — that had to be a good sign. I took a step towards Molly to see if she was okay, but she flung her arm in my direction, palm out, and made violent pushing gestures, so I backed off.

I found myself sitting down again without any memory of wanting to. I was short of breath and I could feel my pulse racing in my throat — all symptoms of blood loss. I decided that it would be a good idea to have a little rest, and I lay back down on the cool tiles, all the better to maintain the blood flow to my brain. It’s surprising how comfortable a hard surface can be when you’re tired enough.

The rustle of silk made me turn my head. Molly, still crouching, had turned away from the slick pool of red vomit and inched towards me. Her head was tilted to one side and her lips were drawn back to reveal her teeth. I was just about to tell her that I was all right really, and didn’t need any help, when I realised that was probably not what she had in mind.

With a disturbingly spider-like motion Molly swung one arm over her head and down until her hand slapped on the tiles in front of her face. The arm tensed and dragged Molly another few centimetres towards me. I looked into her eyes and saw that they were all black, with no trace of white at all, and filled with hunger and despair.