'What on earth are you doing walking around with that on you?' asked Vince.

'I thought it would be safer if I kept it with me. Fucking hell, don't shout, I've had a hard night. I had to take this off some geezer who'd nicked it from my flat.'

'Louie, what are you doing here?' asked Pam. 'Is he all right?'

'He's a bit distraught.' Vince looked from one to the other.

'Are we expecting anyone else? Perhaps you've invited my mother along too?'

'No, there's just us. I thought you'd be pleased.'

Vince shook his head in defeat. 'Well, now that everyone's here, I guess you might as well help. But when they find out, believe me, there's going to be trouble about this.'

Caton-James lifted his legs from the desk and tipped his chair away from the monitors. 'That's it,' he said, 'that's enough.' He punched out Sebastian's number and waited for him to answer. 'He's having a fucking school reunion party outside the cemetery,' he complained, 'standing there talking to his friends in the pissing rain like it's all some big joke. Either you stop this farce now or -'

'Or what?' asked Sebastian.

'We've got enough. This is the seventh, and seven should do it. We've won. We can get rid of the others.'

'No. I want them all.'

'Why do you need the other three, for God's sake?'

'It's foolproof then. Ten out of ten, don't you see? No other explanation needed.'

'All right, but we have to get rid of his friends, and do it right now.'

'I'll have to agree with that. What do you suggest?'

'Where's Xavier?'

'He should be somewhere near the cemetery by now. He's supposed to be keeping Reynolds in his sights. You'd better give him a call.' The line fell silent for a moment. 'God knows how he's supposed to get the bodies from there to the river without arousing suspicion. He'll need a larger vehicle than his bike, that's for sure. Have we got any cars in the area?'

'The Rover's nearby, but it'll need a driver, someone who can keep his mouth shut.'

'Wake up Protheroe. He's monitoring CCTVs for us at Liverpool Street station. Get him out on the street. The fresh air will do him good.'

'I'll stay on this side and keep a lookout,' whispered Pam, even though the street was deserted. 'I'm not fond of cemeteries.' Rain dropped straight and hard on her head and shoulders. The noise of the downpour drowned out any other sound. The colour of her soaked navy-blue suit had run, staining her blouse and her tights. It looked like someone had thrown several pots of ink at her. She would make sure that Vince bought her a new outfit if they survived the night.

The cemetery was sectioned off to protect its more fragile homes. The headstones were tall and thin, often the size of a man, and most had been blown flat by bombs during the Second World War, although their owners were among the few residents in the area who had not lain awake all night waiting for the engines of the V1s to cut out overhead. Louie and Vince found nothing remotely elfish on or around any of the graves. The more famous, and therefore more visited, tombstones had all been repositioned in the centre of the cemetery, on or around its gravel path. The place had lost the chaotic untidiness it had possessed between the wars, and looked the worse for it.

'It would help if we knew what we were looking for,' Louie complained. 'I've never heard of any bloody Elf King.'

It was eerie here even in broad daylight, but worse now with the rain spattering from the claw-like branches of the plane trees, and the streetlamps strobing jaundiced shadows. Beyond the cemetery railing, Pam wrapped her arms around her dripping jacket and tried to stamp some life back into her frozen feet. In doing so, she broke the heel of her shoe. She was staring down at the fracture, trying to think of a way to mend it when she saw the embossed lettering.

'Oh my God. Vince! Louie!' She threw a discreet distress call over the cemetery wall and waited for a response, but none was forthcoming. 'Vince?'

She looked back at the raised metal letters of the manhole cover. It read METROPOLITAN WATER BOARD SV SELF LOCKING PLATE, but the lettering on either side of the cover had worn down to leave the central raised section – ELF KING.

What did the instructions say?

Go below.

Carefully hitching up her soaked skirt, she pulled at the sides of the iron disc and found that it had already been loosened. It shifted easily, so that she was able to roll it aside and stare down into distant rushing darkness.

THE IRON-RUNGED ladder was so cold she was afraid for a moment that her hands might stick to it. She fixed the pen-light torch Vince had left her in the belt-loop of her skirt, and its narrow pool of light instantly revealed the stark white oblong of the letter, weighted down with a piece of brick on a dry stone ledge ten feet underneath her. The rushing water below must surely contain sewage; she imagined that the SV on the manhole cover stood for 'Sewage Valve', but in this cold temperature it thankfully had little odour. Climbing into a sewer during a thunderstorm in high-heels was not something she had ever intended to do in her lifetime. She knew she should have waited for Vince and Louie to come back, but it was a chance to prove herself and do something proactive. It was time women took more of an initiative, she told herself.

It was an easy climb, despite the fact that the drain was narrow and one of her heels was broken. She collected the letter from the ledge, tossing the brick that pinned it into the black waters, then folded the paper and slipped it into her handbag.

She started up the ladder again. At the top, she lobbed her bag back onto the pavement and was about to climb out when the manhole cover abruptly slid back in place with a clang, catching her on the side of the head, and she dropped from the ladder, down into the roaring black spray.

'She drowned,' said Harold Masters. 'It was an accident. The hour was late, the girl was high, on drugs, on drink. It was his son's party, and the boy was blamed. Twenty-one years of age. His nascent career never recovered after that. Surely that's enough to make anyone bitter.'

Bryant pushed a sheaf of clippings in his colleague's direction. 'Come on, Harold,' he said, 'just look at Wells's background. He comes from a long line of empire builders, the so-called backbone of the nation. Sebastian's future had been decided for him before he was even born. His father was a supporter of Mosley, a hardline member of the League of Prometheus, its president for a number of years at a time when their membership was swollen with patriots, and his son took up the life almost at once. Look at his extracurricular track record at Oxford. He was set on becoming a leader of men. And yet he ruins his chances with this one slip-up.'

'It's a human life we're talking about,' said Maggie, 'not just a "slip-up". Besides, a lot of bright young men and women lost their way during their college years.'

'I know, but this doesn't ring true,' complained Bryant, rubbing a weary hand across his face. 'There's something else.'

'Well, I don't know what you expect to find,' said Purbrick. 'The son simply went to the bad.'

'Try reading the clippings chronologically,' Bryant suggested.

'Really, I don't see how this will help.'

'Something happened between Wells pere et fils. Look at this, in 1988 they shared a platform at a local rally, completely in agreement. The following year, the same thing, joint appearances and then – 1990, the son appears alone, and the father has suddenly retired from public speaking. The son even speaks out in public against his own father, who by this time has changed his political affiliations. And this girl drowned in the summer of 1989. Now what does that suggest to you?'