He stared, his eyes gaunt. After a long pause, he said, "Yes."

"Thomas, after Gervase and Ferdinand left Quantum, did you or they make any more of them?"

Berenice interrupted, "Dear Thomas couldn't make a time-switch to save his life, could you, darling?" Her voice was pitying, sneering, unkind. Thomas sent her a haunted look but no protest.

"Someone gave Robin and Peter a Mickey Mouse clock with white plastic-covered wires stuck on it," I said. "Very bright and attractive."

Thomas shook his head helplessly.

"In the rubble at Quantum, they've found a clock hand stuck onto some white plastic-covered wire."

"Oh, my God," Thomas said miserably.

"So what?" Berenice demanded. "Dear Thomas does over-act so."

"So," I said, "someone who knew how to make these time-switches blew up Quantum."

"What of it?" she said. "I can't see Thomas doing it. Not enough nerve, have you, darling?"

Thomas said to me, "Have a drink?"

Berenice looked disconcerted. Asking me to have a drink had been for Thomas an act of rebellion against her wishes. There hadn't been many of them, I guessed. I accepted with thanks, although it was barely five-thirty and to my mind too early. I'd chosen the hour on purpose, hoping both that Thomas would have returned from his day's wanderings and that the daughters would stop at their grandmother's house on their way home from school.

Thomas squeaked across the floor to the kitchen, which was divided from the main room only by a waist-high counter and began opening cupboards. He produced three tumblers which he put clumsily on the counter and then sought in the fridge interminably for mixers. Berenice watched him with her face screwed into an expression of long-suffering impatience and made no move to help.

"We have some gin somewhere," he said vaguely, having at last found the tonic. "I don't know where Berenice puts things. She moves them about."

"Dear Thomas couldn't find a book in a library."

Thomas gave her a look of black enmity which she either didn't see or chose to ignore. He opened another cupboard, and another and in his wife's continued unhelpful silence finally found a nearly full bottle of Gordon's gin. He came round into the main room and poured from the bottle into three glasses, topping up inadequately from a single bottle of tonic.

He handed me a glass. I didn't much care for gin, but it was no time to say so. He held out the second glass to Berenice.

"I don't want any," she said.

Thomas's hand was trembling. He made an awkward motion as if to raise the glass to his own lips, then put it down with a bang on the counter and in an uncoordinated movement accidentally knocked the gin bottle over so that it fell to the floor, smashing into green shiny pieces, the liquid spreading in a pool.

Thomas bent down to pick up the bits. Berenice didn't help. She said, "Thomas can't get anything right, can you, darling?"

The words were no worse than others, but the acid sarcasm in her voice had gone beyond scathing to unbearable.

Thomas straightened with a face filled with passionate hatred, the worm turning at last, and by the neck he held the top part of the green bottle, the broken edges jagged as teeth.

He came up fast with his hand rising. Berenice, cushioned in complacency, wasn't even looking at him and seemed not to begin to understand her danger.

Malcolm said I had fast reactions… I dropped my own drink, grasped Berenice by both arms and swung her violently round and out of the slicing track of the razor-sharp weapon.

She was furiously indignant, protesting incredulously, sprawling across the floor where I'd almost thrown her, still unaware of what had been happening.

Thomas looked at the damage he'd done to me for a long blank second, then he dropped the fearsome bottle and turned to stumble off blindly towards his front door. I took two strides and caught him by the arm.

"Let me go…" He struggled, and I held on. "Let me go… I can't do anything right… she's right."

"She's bloody wrong."

I was stronger than he. I practically dragged him across the room and flung him into one of the armchairs.

"I've cut you," he said.

"Yes, well, never mind. You listen to me. You both listen to me. You're over the edge. You're going to have to face some straight facts."

Berenice had finally realised how close she'd come to needing stitches. She looked with anger at the point of my left shoulder where jersey and shirt had been ripped away, where a couple of cuts were bleeding. She turned to Thomas with a bitterly accusing face and opened her mouth.

"Shut up," I said roughly. "If you're going to tell him he's incompetent, don't do it. If you're going to complain that he could have cut you instead, yes he could, he was trying to. Sit down and shut up."

"Trying to?" She couldn't believe it. She sat down weakly, her hair awry, her body slack, eyes shocked.

"You goaded him too far. Don't you understand what you've been doing to him? Putting him down, picking him to pieces every time you open your mouth? You have now completely succeeded. He can't function any more."

"Dear Thomas -" she began.

"Don't say that. You don't mean it."

She stared.

"If he were your dear Thomas," I said, "you would help him and encourage him, not sneer."

"I'm not listening to this."

"You just think what you stirred up in Thomas today, and if I were you, I'd be careful." I turned to Thomas. "And it's not all her fault. You've let her do it, let her carp all this time. You should have stopped her years ago. You should have walked out. You've been loyal to her beyond reason and she's driven you to want to kill her, because that's what I saw in your face." Thomas put a hand over his eyes.

"You were dead lucky you didn't connect with her mouth or her throat or whatever you were going for. There would have been no going back. You just think what would have happened, both of you. The consequences to yourselves, and to your girls. Think!" I paused. "Well, it's beyond facing."

"I didn't mean it," Thomas mumbled.

"I'm afraid you did," I said.

"He couldn't have done," Berenice said.

"He did mean it," I said to her. "it takes quite a force to tear away so much woollen jersey. Your only hope is to believe to the depths of your soul that he put all his goaded infuriated strength behind that blow. I'll tell you, I was lucky too. I was moving away fast trying to avoid being cut, and it can have been only the points of the glass that reached my skin, but I'll remember the speed of them…" I broke off, not knowing how else to convince her. I didn't want to say, "it bloody hurts," but it did.

Thomas put his head in his hands.

"Come on," I said to him, "I'm taking you out of here. On your feet, brother."

"Don't be ridiculous," Berenice said.

"if I leave him here, will you cuddle him?"

The negative answer filled her whole face. She wouldn't have thought of it. She was aggrieved. It would have taken little time for her to stoke up the recriminations.

"When the firemen have gone," I said, "fires often start again from the heat in the embers." I went over to Thomas. "Come on. There's still life ahead."

Without looking up, he said in a dull sort of agony, "You don't know… It's too late."

I said "No" without great conviction, and then the front door opened with a bang to let in the two girls.

"Hello," they said noisily, bringing in swirls of outside air. "Granny turned us out early. What's going on? What's all this glass on the floor? What's all the blood on your arm?"

"A bottle got broken," I said, "and I fell on it."

The young one looked at the bowed head of her father and in a voice that was a devastating mimic of her mother's, vibrating with venom and contempt, she said, "I'll bet it was Dear Thomas who broke it."