‘And what’s that?’ asked Gareth.

‘Not what,’ said Evi. ‘Who. I think the link is Gillian.’

Tom was awake. Had he been asleep? He thought perhaps he had but he wasn’t sure. Whose bed was he in? Joe’s. The canopy of his own bunk was several feet above his head. There was light in the corridor, and he could hear voices in the kitchen downstairs. Not that late then. Better go back to sleep. Sleep was a world in which Joe was still OK.

A sudden rattling sound. He sat up. That was what had woken him. A series of sharp, clear taps. Someone was throwing stones at the window.

Joe! Joe was back and trying to get in. Tom sprang out of bed and ran across the room. The curtains were drawn. The fabric was rough against his face and he could feel the draught from outside. ‘Joe,’ he whispered.

He could still hear voices downstairs. Harry’s was the loudest, the most distinct. He could hear a woman’s voice too, much softer and quieter. Not his mum though, someone with an English accent. It could be Jenny, she’d been here earlier. Should he call for his parents, tell them he thought Joe was outside, throwing stones up at the window?

But could he do that to his mum? Make her hope Joe was back when really it was just tree branches scraping against the window?

There were no trees anywhere near Tom’s bedroom window.

He put both hands on the curtains and got ready to pull them an inch or two apart. Just far enough to see what was out there. An inch. Nothing but blackness. Two inches. Three.

The girl was in the garden behind the house, staring up at him.

In the kitchen silence fell. Then Gareth pushed himself to his feet. Rushton held up one hand. ‘Mrs Royle should be on her way to headquarters by now,’ he said, looking at his watch. ‘I’m just waiting for a call from DI Neasden to tell me she’s safely in custody. We won’t be able to interview her until the duty psychiatrist is in attendance, but at least we know she won’t be able to harm the lad.’

‘Gillian?’ said Alice. ‘Hayley was her daughter.’

‘She wouldn’t be the first mother to kill her own child,’ answered Rushton. ‘Not by a long shot. To be honest, I was sceptical myself when Dr Oliver called. I’m still not 100 per cent convinced, but there are enough questions that need answering.’ He nodded at Evi. ‘Go on, lass,’ he said, ‘you’ll tell it better than I will.

Evi dropped her eyes to the table, then looked up again. ‘I’ve been worried about Gillian for a while,’ she said, and the words seemed to come out of her reluctantly, as though, even now, she found it hard to break a patient’s confidence. ‘I knew there was a lot she wasn’t telling me, and I also knew there was more going on in her head than grief. I’ve suspected childhood abuse from a number of things she’s said and the behaviour she exhibits, but the first really worrying sign for me was finding out she’d lied about the manner of Hayley’s death. She told me and others that Hayley’s body wasn’t found, that it just disappeared in the fire. That wasn’t true. The firemen found remains.’

‘Which weren’t Hayley’s,’ Harry reminded her. ‘Hayley was taken out before the fire was started.’

‘Yes,’ said Evi. ‘But how could she have known that unless she was involved in Hayley’s removal from the cottage? I think Gillian’s refusal to accept that the remains were Hayley’s was her way of dealing with guilt.’

‘OK, but that’s not enough by itself,’ said Harry, looking up at Rushton, trying to read the older man’s face.

Evi sipped from her glass again. ‘No, it isn’t,’ she said. ‘But I’ve been talking to her mother as well, over the last week or so. Gillian’s father was killed in a car accident when she was three. She was in the car with him. She wasn’t hurt, but when the police pulled her out she was covered in her father’s blood.’

‘Christ,’ muttered Gareth.

‘Well, yes. Enough to have a damaging effect on any child. Gillian’s mother married again and – I have no proof of this, but I think Gillian was abused by her stepfather when she was still quite young. Her early medical history shows textbook examples of symptoms of abuse and she talks about him in a way that is very disparaging and full of sexual references. I’ve had to be very careful when I’ve been talking to Gwen. Obviously, I couldn’t ask her outright if Gillian had been abused, but I could hint around the subject. There was something there, I’m sure of it. Gwen knows more than she’s saying. Then when Gillian was twelve her eighteen-month-old sister was killed. She fell from the top of the stairs at her home and landed on the stone floor. Sound familiar to anyone?’

Harry saw Alice reach back and take hold of her husband’s hand. Neither seemed capable of speaking.

‘It’s worrying,’ said Harry, looking at Rushton again. ‘But isn’t it what you call circumstantial?’

‘Her stepfather found the child, but Gillian was in the house too,’ said Evi, before Rushton could respond. ‘She would have seen the blood, heard the man she hated howling in agony. That could make a disturbed teenager feel pretty powerful.’

‘It’s still speculative, Evi,’ said Harry.

‘That’s what I was saying at this point,’ said Rushton, nodding his head.

‘Gillian’s husband was cheating on her,’ said Evi. ‘I think she killed Hayley to punish him, the way she punished her stepfather by killing his daughter. She kills because it makes her feel powerful. Gillian and her mother were at the Renshaws the day Lucy was killed.’

‘Gwen told you that?’ asked Harry. He thought for a second. ‘Actually, I think I knew that. I think Jenny mentioned it herself.’

‘Gillian helped to look after Lucy sometimes, she was a sort of unofficial nanny,’ said Rushton. ‘And she used to babysit for Megan. Of course, we can’t guess why she would want to kill those two, but as I say, questions need to be asked.’

For a moment no one spoke.

‘Gillian was seen catching a bus to Blackburn early yesterday afternoon,’ said Evi.

Still silence.

‘She knew about the pantomime,’ said Alice. ‘She was round here yesterday morning with Jenny. I told her where the boys would be.’

Treading softly with bare feet, Tom made his way down the stairs. The kitchen door was closed. He could hear several voices behind it. He stepped into the living room and crossed to the window that overlooked the garden. It wasn’t easy, pulling back the curtain, she would be so much closer now, but somehow he managed it.

Two eyes. Large and brown, with crepey, wrinkled skin around them, wrinkles that made her look old and not old at the same time. Two eyes staring in at him, with an expression he’d never seen before. He’d seen her full of mischief. He’d seen her threaten him and Millie. He’d never seen her scared.

‘Ebba.’ No sound came out, his lips were forming the words.

‘Tommy,’ she mouthed back.

He stepped away, allowing the curtains to fall back into place. She rapped softly on the window.

What should he do?

If he yelled for his dad, she’d go. And he wanted her to go. It was bad enough without Joe, he couldn’t deal with monsters too.

Tap, tap, tap. Louder this time. He had to make a decision before she broke the glass.

Silence. He reached out and moved the curtain. She was still there. When she saw him she pointed at the window lock, her hand jabbing up and down. She wanted him to open the window. She wanted to come in.

Not in a million years. He opened his mouth to yell.

She might have Joe.

He didn’t care, he wasn’t that brave, she wasn’t coming in. He shook his head and took a step back into the room. The curtains fell back but didn’t quite meet. He could still see her. He saw her reach down into the neck of her dress and pull something out. He saw her press it against the glass.

She did have his brother. How else could she have got hold of Joe’s trainer?

Tom couldn’t stop himself taking a step closer to the glass. When he and Joe had got their new trainers they’d customized them. They’d put stickers on the heels and swapped laces, so that Tom’s mainly black trainers had red laces and Joe’s mainly red trainers had black laces. A red trainer with a black lace was being pressed against the glass and the remains of a Spiderman sticker were visible on the back of the heel.