It was very cold in the crypt. Conversation had died. They stood in a ring looking at the row of skulls as if these smooth domes of bone, the ragged nasal orifices, the gaping sockets, could be made to yield the secret of their deaths. How unfrightening they were, thought Cordelia, these age-long symbols of mortality, set up like a row of grinning devils to frighten children at a fairground and, in their denuded anonymity, stripping human pretensions to the risible evidence that what lasted longest in man were his teeth.

From time to time during Ambrose's story she had glanced at Clarissa, wondering what effect this recital of horrors might have on her. It seemed to her strange that the crudely drawn caricature of a skull could produce such fear while the reality provoked no more than an exaggerated frisson of distaste. But Clarissa's refined sensibilities were apparently capable of sustaining any amount of assault provided the horrors were anaesthetized by time and there were no threats to herself. Even in the harsh, draining glare of the crypt her face looked flushed and the immense eyes shone more brightly. Cordelia doubted whether she would be happy to visit the crypt alone but now, feeling herself the centre of the company, she was enjoying a thrill of vicarious dread like a child at a horror movie who knows that none of the terror is real, that outside is the familiar street, the ordinary faces, the comfortable world of home. Whatever Clarissa feared, and Cordelia couldn't believe that the fear was faked, she had no sympathy with these long-dead tormented souls, no dread of a supernatural visitation in the small hours. She was expecting that, when her fate came and in whatever guise, it would still wear a human face. But now excitement had made her euphoric. She said to Ambrose:

'Darling, your island's a repository of horrors, charming on the surface and seething underneath. But isn't there something closer in time, a murder which really did happen? Tell us about the Devil's Kettle.'

Ambrose avoided looking at her. One of the skulls was unaligned with its fellows. He took the white ball between his hands and tried to grind it back into place. But it couldn't be shifted and, suddenly, the jaw bone came apart in his hands. He shoved it back, wiped his hands on his handkerchief and said:

'There's nothing to see. And the story is rather beastly. Only interesting really to those who relish in imagination the contemplation of another's pain.'

But the warning and the implied criticism were wasted on her. She cried:

'Darling, don't be so stuffy! The story's forty years old at least and I know about it anyway. George told me. But I want to see where it happened. And I've got a personal interest. George was here on the island at the time. Did you know that George was here?'

Ambrose said shortly:

'Yes, I know.'

Roma said:

'Whatever it is, you may as well show us. Clarissa won't give you any peace until you do and the rest of us are entitled to have our curiosity satisfied. It can hardly be worse than this place.'

No one else spoke. Cordelia thought that Clarissa and her cousin were unlikely allies even in persuasion and wondered whether Roma was genuinely interested or merely hoped to get the story over with so that she could get out of the crypt. Clarissa's voice assumed the wheedling note of an importunate child.

'Please, Ambrose. You promised that you would some time or other. Why not now? After all, we're here.'

Ambrose looked at George Ralston. The look seemed to invite consent, or at least comment. But if he were hoping for support in resisting Clarissa, he was disappointed. Sir George's face was impassive, its restlessness for once stilled.

Ambrose said:

'All right, if you insist.'

He led them to a low door at the west end of the crypt. It was made of oak, almost black with age and with strong bands of iron and a double bolt. Beside it on a nail hung a key. Ambrose shot back the bolts then inserted the key in the lock. It turned easily enough but he needed all his strength to pull open the door. Inside he reached up and switched on a light. They saw before them a narrow vaulted passage only wide enough for two to walk abreast. Ambrose led the way with Clarissa at his shoulder. Roma walked alone followed by Cordelia and Simon with Sir George and Ivo at the rear.

After less than twenty feet, the passage gave way to a flight of steep stone steps which curved to the left. At the bottom it widened but the roof was still so low that Ivo had to stoop. The passage was lit by unshaded but protected light bulbs hung from a cable and the air, although fusty, was fresh enough to breathe without discomfort. It was very quiet and their footsteps echoed on the stone floor. Cordelia estimated that they must have covered about two hundred yards when they came to a turn in the passage and then a second flight of steps, steeper than the first and rougher, as if hewn out of the rock. And it was then that the light failed.

The shock of instantaneous and total blackness after the artificial brightness of the tunnel made them gasp and one of the women – Cordelia thought that it was Clarissa – gave a cry. She fought against a moment of panic, calming by an act of will her suddenly pounding heart. Instinctively she stretched out her hand into the darkness and encountered a firm warm arm under thin cotton, Simon's arm. She let go but almost immediately felt her hand grasped by his. Then she heard Ambrose's voice.

'Sorry, everyone, I'd forgotten that the lights are on a time switch. I'll find the button in a second.'

But Cordelia judged that it must have been fifteen seconds before the light came on. They blinked at each other in the sudden glare, smiling a little sheepishly. Simon's hand was immediately withdrawn as if scalded and he turned his face from her. Clarissa said crossly:

'I wish you'd warn us before playing silly tricks.' Ambrose looked amused.

'No trick I assure you. And it won't happen again. The chamber above the Devil's Kettle has an ordinary light system. Only another forty yards to go. And you did insist on this excursion, remember.'

They went down the steps with the aid of a looped rope which had been threaded through rings bolted into the rock. After another thirty yards the. passage widened to form a low-roofed cave. Ivo asked, his voice sounding unnaturally loud:

'We must be forty feet below ground. How is it ventilated?'

'By shafts. One of them comes up into the concrete bunker built in the war to guard the southern approach to the island. And there are a number of others. The first of them is believed to have been installed by de Courcy. The Devil's Kettle must have had its uses for him.'

In the middle of the floor was an oak trapdoor furnished with two strong bolts. Ambrose drew them back and pulled open the flap. They crowded round and six heads bent to peer down. They saw an iron ladder leading down to a cave. Below them heaved sea water. It was difficult to tell which way the tide was running but they could see the light streaming in from- an aperture shaped like a half moon and they heard for the first time the faint susurration of the sea and smelt the familiar salty seaweed tang. With each wave the water gushed almost silently into the cave and swirled around the rungs of the ladder. Cordelia shivered. There was something remorseless, almost uncanny, about that quiet, regular spouting. Clarissa said:

'Now tell!'

Ambrose was silent for a minute. Then he said:

'It happened in 1940. The island and the castle were taken over by the Government and used as a reception and interrogation centre for foreign nationals of the Axis powers trapped in the United Kingdom by the war, and others, including a number of British citizens who were suspected, at worst, of being enemy agents or at best of being Nazi sympathizers. My uncle was living in the castle with only his one manservant and they were moved out to the cottage in the stable block now occupied by Oldfield. What went on in the castle was, of course, top secret. The internees were only kept here for a relatively short time and I've no reason to suppose that their stay was particularly uncomfortable. A number were released after interrogation and clearance, some went on to internment on the Isle of Man, some I suppose eventually came to less agreeable ends. But George knows more about the place than I do. As Clarissa says, he was stationed here as a young officer for a few months in 1940.'