‘What did that?’ I asked.
‘River spirits,’ said Nightingale. ‘Stay here while I check further up the bank.’
I heard another laugh from across the water. Then, very clearly and not three metres from where I was standing, someone, definitely a woman and a Londoner, said, ‘Oh, shit!’ Then came the sound of metal being torn.
I ran over. At that point the bank was a muddy slope held together with tree roots and bits of stone reinforcement. As I got close I heard a splash, and got my torch on it just in time to see a sleek curved shape vanish beneath the surface. I might have thought it was an otter, if I was stupid enough to think otters were hairless and grew as big as a man. Just below my feet was a square cage made out of chickenwire, part of an anti-erosion project I learned later, one side of which had been torn open.
Nightingale returned empty-handed and said that we might as well wait for the fire boat to come and take the remains of the narrowboat under tow. I asked him if there was such a thing as mermaids.
‘That wasn’t a mermaid,’ he said.
‘So there are such things as mermaids,’ I said.
‘Focus, Peter,’ he said. ‘One thing at a time.’
‘Was that a river spirit?’ I asked.
‘Genii locorum,’ he said. ‘The spirit of a place, a goddess of the river, if you like.’ Although not the Goddess of Thames herself, Nightingale explained, because her taking a direct part in any aggro would be a violation of the agreement. I asked whether this was the same agreement as ‘the agreement’， or a different agreement entirely.
‘There are a number of agreements,’ said Nightingale. ‘A great deal of what we do is making sure everyone keeps to them.’
‘There’s a goddess of the river,’ I said.
‘Yes – Mother Thames,’ he said patiently. ‘And there’s a god of the river – Father Thames.’
‘Are they related?’
‘No,’ he said. ‘And that’s part of the problem.’
‘Are they really gods?’
‘I never worry about the theological questions,’ said Nightingale. ‘They exist, they have power and they can breach the Queen’s peace – that makes them a police matter.’
A searchlight stabbed out of the darkness and swept over the river once, twice, before swinging back to fix on the remains of the narrowboat – the London Fire Brigade had arrived. I smelled diesel exhaust as the fire boat gingerly manoeuvred alongside, figures in yellow helmets waiting with hoses and boathooks. The searchlight revealed that the superstructure had been completely gutted by the fire, but I could see that the hull had been painted red with black trim. I could hear the firemen chatting to each other as they boarded and made the narrowboat safe. It was all reassuringly mundane. Which brought me to another thought. Nightingale and I had scrambled out of bed, into the Jag and headed west before there was any indication that this was nothing more than the tail end of an average Friday night.
‘How did you know this was our shout?’ I asked.
‘I have my own sources,’ said Nightingale.
One of the Richmond IRVs arrived with the Duty Inspector onboard and we all indulged in a bit of bureaucratic strutting to establish our respective bona fides. Richmond won on points, but only because one of them had a flask full of coffee. Nightingale briefed the locals – it was a gang thing, he said. Some IC1 youths, no doubt drunk, had stolen a boat, sailed down from beyond Teddington Lock and picked a fight with a local group of IC3 youths – some of whom were female. When they tried to escape, the Teddington gang had managed, accidentally, to set their boat on fire, had abandoned ship and escaped on foot down the Thames pathway. Everybody nodded their heads – it sounded like a typical Friday night in the big city. Nightingale said he was sure nobody had drowned, but the Richmond Duty Inspector decided to call in a search-and-rescue team just in case.
Then, our two inspectors having marked their respective trees, we went our separate ways.
We drove back up to Richmond but stopped well short of the bridge. Dawn was at least an hour away, but as I followed Nightingale through an iron gate I could see that the road we were on cut through a municipal gardens that sloped down to the river. There was an orange glow ahead of us, a hurricane lantern hung on the lower branches of a plane tree, and it illuminated a row of red-brick arches built into the revetment that supported the roadway. Inside these artificial caves I glimpsed sleeping bags, cardboard boxes and old newspaper.