'They fell out over the girl's death,' said Jane. 'It would be more surprising if they hadn't. Where was the mother while all this was going on?'

'She dropped out of the picture some years earlier. Lives in France.'

'Later the father took to the lecture circuit without his son,' Masters pointed out. 'He remained a Conservative, but his position was shifting. Getting soft in his dotage, the son told the papers. Sebastian kept a hard line on immigration, while his father founded that initiative, the Without Borders thing. Supposed to bring down trade barriers. Although I imagine the old man set it up so that his business interests would benefit from changes in the migration laws, bring more wage slaves into Britain, that sort of malarkey. Their flags are out all along the Mall this week. There must be something going on.'

'It's as if father and son were competing with one another,' muttered Bryant.

'That's right. Sebastian is fresher, younger, the stronger of the two. He had an advantage over the old man, he was heading for the top. Then the scandal of Melanie Daniels's death hit him, and he never recovered his credibility. In the battle of ideologies, the father somehow won. This is very curious.'

'I really don't see what's so odd,' said Maggie impatiently, 'or how it helps anyone. We should be helping Vince find this Elf King.'

'He's looking for it now,' said Masters. 'I'm sure he'll call us as soon as he has news. I'm going upstairs to check on something. Bryant, will you come with me?'

'Certainly, old man. You know, I have an idea…' 'We should never let those two get together,' said Jane, wearily pouring herself a scotch. 'Heaven knows what they'll hatch up.' It was safe to assume that she would be preparing a cooked breakfast for five this morning, shortly after the arrival of dawn. The Insomnia Squad had passed long nights before, but never anything like this.

'She wouldn't have just left it here,' said Vince, picking up the sodden bag and turning it by its strap. 'She must be around somewhere.' Louie walked to the corner and returned. 'Nope, no sign of anybody.'

'Didn't you hear anything?'

Louie narrowed his eyes, the rain spattering across his forehead. Above him, thunder grumbled. 'In this?'

'She wouldn't have left without me.' Vince opened the bag and peered in. He instantly recognised the envelope. 'Looks like she found it.' He pulled it out, noting that it had not been opened.

'Where, though? Where was she standing just before I climbed over the railings after you?' They looked around, but it was still a few minutes before they saw the manhole lid.

Whoever had put it back had stamped it into place, knocking off pieces of the paving stone's cement edging. The cover was now firmly jammed. Louie searched around for some kind of lever, and picked up a broken section of branch. He tried to wedge it under one end of the lid, but the wood was wet, and split. Vince found a discarded hubcap in the gutter and after chipping away at the cement edging they jammed it beneath the edge of the lid, but it took another five minutes to prise the iron disc from its setting.

'Aqua Mortis,' said Louie, kneeling and peering into the blackness. 'That's what they used to call the Thames. Water of death. So much sewage flowed into it. The stench alone was enough to kill you. You don't think she's down there, do you?'

'With the Elf King? Somebody pulled the thing up. Pamela!' yelled Vince, but the cry was lost in the noise of churning water. The pipes were thumping and gurgling with the deluge of torrential rain. It was a pity he had given his torch to Pam. He could see no more than three or four feet into the top of the shaft.

'I don't think I can go down there,' said Louie. 'I get claustrophobia.'

'Suppose she reached up to throw the bag out and the lid fell back on her, knocking her down the steps to the bottom? She might be just out of reach, unconscious.'

'And she might be dead. Suppose there's someone else here? You yourself said they don't want you talking to anyone.'

Vince stared at Louie. 'You know we have to go and look.'

'Shit.'

The next sound to pass between them was that of an arrow cleaving the air. Louie looked back at Vince's wide eyes and dropping jaw, then down at the side of his own thigh, from which protruded six inches of slim aluminium shaft. 'Man, I don't believe it,' was all he managed to say before Xavier Stevens kicked him over the manhole-mouth. Vince scrambled to his feet and heard the crossbow reload in his direction. Louie tried to maintain his balance but fell back into the sewage shaft.

The water level had risen since Pam climbed down to retrieve the letter. There was a scrape of brickwork and an echoing splash when Louie hit the bottom.

Stevens kicked the heavy lid back into place again, stamped it hard into the surround with a steel-capped boot and hesitated in front of Vince, staring him down, daring him to move. He was tempted to finish the job and face the consequences later. He wasn't afraid of anything Sebastian might threaten him with. But then his bloodlust subsided, and he began thinking practically. He'd done the League a favour. Caton-James had called him to say that Protheroe was bringing something to put the bodies in, but he would not be needed now. Stevens returned to his motorbike and kicked it into life. This night was going to cost Sebastian dearly. They were going to discover that his silence had a painfully high price.

Vince helplessly tried to tear the lid from the drain, but it was too firmly wedged in place now to shift without tools. He darted across the road and hammered on the door of the saloon bar, but no lights came on, no heads appeared at the windows above. Running around the corner, he rang the bell of the first flat he chanced upon. No answer again. Given the late hour and the inclemency of the weather, it was hardly surprising that no one was prepared to open their door to a stranger in the street.

Returning to collect Pam's fallen bag, he removed her mobile phone, walked back to the comparative shelter of the pub doorway and punched out Masters's number. The doctor answered on the second ring, listened to what had happened and promised to call the police immediately.

'I can't get the lid up by myself,' Vince shouted above the drumming rain, 'it's stuck in place.'

'You mustn't panic,' said Masters. 'Let's think this through. In normal weather he'd probably be able to go along to the next valve shaft and surface there, but in this downpour the tunnel may well be flooded all the way to the roof. Jane's calling the police on our other line, Vince. You'd better get away from there fast.'

'I can't just leave them like this. Jesus, they might both be -'

'There's nothing more you can do, is there?'

'Not without equipment, people to help me -'

'Exactly. If you stop now, they'll have suffered for no purpose. You have to keep going.'

'I can't -'

'You can. You say you have the new envelope. Have you opened it yet?'

'No,' he said, 'Jesus Christ -'

'If you don't do it and stay calm, Vince, everything is lost.'

'Okay. Hold on.' He pulled the sopping letter from his pocket, tore off the end and attempted to read the paper inside.

The Challenge Of The Hours

The night of September 3rd and the passing of Proserpine.

A Sunday evening near Sadler's Wells with Diana and her cuckold Actaeon.

Noon at L'Eglise des Grecs in Hog Lane, where a good woman is silent.

Aurora arrives at St Paul's at five to eight, less pious than she appears.

The words had been transcribed with a fountain pen as usual, and were once again in a different hand. It was a wonder the rain had not ruined them. He wondered what effect water would have on the chemical treatment of the paper. Vince read the letter aloud, pausing to allow the doctor time to jot each sentence down.