"I, Zanny Moncrief," she wrote, "being of sound mind and body did on" (she couldn't remember the date) "a day in early summer go up on the headland in Coracle Bay while on a school picnic and push Miss Bridget O'Hare over the cliff and into the sea where she died. Ignatius Murphy was not there when it happened. He has been falsely accused of Miss O'Hare's murder and must be set free."

She signed it Susannah Moncrief and put Zanny in brackets.

Just as she finished writing it, Constable Williams knocked at the door and came in. "There's an unexploded bomb in the backyard," he said.

Thomas, deploring his humour, and forgetting he had told him to rescue him in ten minutes, told him icily to leave them alone.

Then he read the statement through. "Good," he said, "very good indeed. Nice writing. Expressed very well."

"And now," said Zanny, "I suppose you'll arrest me." She felt very tired.

Thomas, too, was tired. It was proving very exhausting trying to explain why an arrest couldn't be made.

"Well, I wish I could," he said. "It's always so much easier to arrest people when you are a hundred per cent sure that you are doing the right thing. But I can't arrest you on this statement alone. There's got to be proof."

"What sort of proof?" asked Zanny.

"Well, somebody seeing you do it, maybe." He thought of the other one waiting outside. "And not your friend," he said hastily. "A complete stranger."

"You mean," Zanny asked aghast, "that if I can't produce a witness, Murphy will die?"

"Oh, I wouldn't say that," Thomas rea.s.sured her. "There's a pet.i.tion going around the town asking for his reprieve. It will go up to the convent and you can put your name on it."

"Did anyone," Zanny asked, "say that they saw Murphy pushing Bridget O'Hare over the cliff?"

"Well - no - not exactly - no . . ." said Thomas. "It's circ.u.mstantial evidence in his case - no witness needed."

Zanny tried to clarify it. "So I would need a witness -and Murphy doesn't?"

"That about sums it up."

"I see," said Zanny, and she thought she did. Some people -- such as herself - could kill with impunity. Some people carried the bugs of disease and didn't get it. Other people, who didn't carry the bugs, did. She, Zanny, could walk through a barrage of gunfire and because of her invisible protection didn't get hit. Murphy wasn't among the lucky ones.

Short of chaining herself to this chair like a suffragette to railings and refusing to budge there was nothing she could do.

"Well," she said. "I've told you."

"Yes," said Thomas, rising, "and you're not to worry any more."

"I think," Zanny said bitterly, "that you're mad."

"No doubt," Thomas replied, quite unruffled. "We're all a little mad. Given time we get better."

He saw her to the door.

This time the telephone call was from him to Mother Benedicta. She listened, appalled. When the old -- such as Miss Sheldon-Smythe - were crazy, it was no great tragedy. But when the young started hallucinating it was serious. She thanked the sergeant for handling it so well. "Oh, I've gels of my own," he said comfortingly. "It's a funny time - adolescence - funny things happen."

Not an adjective I'd use, Mother Benedicta thought.

"The last time we had a murder in the town and the murderer was due to hang," Thomas said, "we had over twenty confessions. The death penalty does that to some people -- upsets them, like."

Mother Benedicta was very sorry indeed that it had upset Zanny. As for Dolly's role - she just couldn't understand it. She was such a sensible, well-balanced girl. How extraordinary that she should aid and abet Zanny in this. And the Moncriefs had been so good to her -- so very good. She decided to write to them. It would be easier to explain on paper. Nothing would be said about Dolly, of course. No point in jeopardising the child's future by antagonising her benefactors. If she was quick the letter would catch the late afternoon post.

Clare and Graham had just made love when the letter arrived. Contraception was no longer a contentious topic between them. Their one child, since the trial and conviction of Murphy, was proving one child too many.

Graham, on his way to the kitchen to put on the kettle for early morning tea, saw the envelope lying on the mat and brought it back to the bedroom. Clare, sleepy, naked, warm with love, was lying sated and happy under the sheet when she heard him tear it open. After a couple of minutes' silence while he read the letter she heard him give a little grunting moan.

"Income tax?" she asked, coming fully awake, "or the electricity bill?"

"Mother Benedicta."

More serious than either. She scrambled up onto her knees and read anxiously over his shoulder.

Mother Benedicta had been as tactful as she possibly could be. She had started by saying what a pleasant, kind, very imaginative child Zanny was. "All the school," she had gone on, "were very disturbed indeed by the appalling tragedy of Bridget O'Hare and the subsequent sentencing of Murphy. I did what I could to minimise the shock of all this; banning newspapers and so on; but the truth couldn't be withheld altogether. Your very dear, very sensitive little daughter, shocked by the horror of the impending death of a man she had seen in the convent gardens (though, not to my knowledge had ever spoken to), became for a while emotionally unbalanced. Unknown to me (the excuse was a visit to the dentist), she went to the local police station and informed the station sergeant that it was she who had murdered Bridget."

"Christ!" said Clare.

She read on. "The sergeant, a sensible man well used to hearing several bogus confessions at times such as this, spoke a few kind words to her and sent her back to the convent. He then telephoned me and told me not to worry about it. Adolescent aberrations, he told me, were not new to him. They were best disregarded.

"I felt his advice was extremely sensible and as from now, obviously I had to tell you though I do regret having to worry you, I believe we should try to put it out of our minds.

"I reprimanded Zanny for going into the town on false pretences. I also told her quite sternly that she should keep her imagination on a tighter rein. She was quite upset at the time and kept insisting on her guilt. As the best way to calm a troubled mind is by filling it with hard work, I arranged for her cla.s.s teacher to give her extra mathematics lessons. Her algebra is particularly weak. I also spoke to Father Donovan so that he might be prepared for a confession along similar lines. A minor penance for what is not only a lie but an emotional and rather unhealthy leaning towards martyrdom should convince Zanny of her folly.

"And so -- Mr. and Mrs. Moncrief -- having dutifully told you what I felt you should know - shall we now thank G.o.d for the sensitivity of a young girl and leave it with G.o.d.

"In a fortnight's time, on the fourteenth of this month, we are holding our Autumn Fair. It is to be opened by Sir Clifford Ponsonby who has recently come to live in the area. I hope as many parents as possible will attend and I shall look forward to your presence. By then I hope Zanny will be her usual cheerful self and that nothing need be said of what has happened."

Clare began to laugh. And then tears edged down her cheeks. "b.l.o.o.d.y silly -" she said. She picked up the pillow and thrust it against her stomach.

Graham dropped the letter and watched it spiral to the floor.

Down below in the kitchen the kettle whistled. He walked down into the steam and made the tea. Today the office could go hang. Blast the word! He put the usual two biscuits on a plate and then the whole lot on a tray and carried it upstairs.

Clare was lying on her side in a foetal position with the pillow still pushed against her stomach, but when he came in she sat up and took the cup from him. She asked him what they were going to do.

He didn't know. At the end of the trial he had half believed in Murphy's guilt. A fifty per cent belief in Zanny's innocence had been comforting. He needed to cling to the comfort. The letter had posed a problem. Like a deep, sinister pool, it was best skirted around while he thought.

"We never knew for sure," he said, "that Zanny drowned little Willie."

He hoped that Clare would see it as a life-line across the pool and use it that way without plunging both of them in. He went on quickly. "Evans the Bread died accidentally. Okay - Zanny pushed Dolly. She might not have realised the van was so near. Children fall into ponds. Children push children. Murphy had a good reason for getting rid of Bridget -- why take it for granted he didn't do it? We didn't see Zanny drown Willie. No one saw her push Bridget. It seems to me we've been in too much of a hurry all these years to see the bad side of her - the bad side that probably doesn't exist."

"Then why did she make the confession to the police?" Clare's little tug on his life-line was malevolent.

He pulled back hard. "To quote Mother Benedicta - a desire for 'martyrdom'."

They looked at each other. And then they looked away.

"If we back Zanny's confession," Clare said, "Murphy will live."