‘No,’ she said. ‘They mean nothing at all. You mean nothing at all.’

She filled the syringe and took a rubber hose from the day pack. She tied it around his upper arm and waited for the vein on the inside of his elbow to pop up.

‘No,’ he said. ‘Don’t do this.’

The tip of the needle pierced his skin and a small bead of blood formed where it had entered. She pressed the plunger and emptied the drug into his arm.

For a few seconds nothing happened, then his jaw slackened and his mouth fell open. His tongue lolled out of it.

He moaned and a look of ecstasy came over his face, then his eyes, already heavy-lidded, started to close.

‘Jo,’ he mumbled. ‘Jo.’

She wiped the vial and the syringe clean of her prints, then pressed them against his fingers and laid them on the bottom of the dinghy. They would follow him to the bottom of the lake – she had an image of them drifting slowly down and settling on Alice Barnes’ corpse, but that was ridiculous as she was on the other shore – but it paid to be cautious.

Then she stood up and turned to the house.

All of a sudden the moment was here. Get the baby, put her on her daddy’s chest, and push the boat out into the water. She’d take it out until it was maybe twenty feet deep, and then tip it over.

Then, in the morning, a panicked phone call to the police.

I woke up and my husband’s not here. I went to bed early last night and he put our daughter to bed. But neither of them are here. I can’t get him on his mobile phone.

Then, after they found the body, back home to take care of the last piece of the puzzle.

Roland. She had to find out what – if anything – he knew. If he knew too much there’d be another overdose. It would be easy enough to explain – a recovering addict falling apart under the stress of his brother’s suicide.

Two brothers dead so close together. An unthinkable tragedy.

Then she heard something. The sound of a car engine. The crunch of tyres on the gravel drive at the front of the house.

Who was this? Who could it be? She ran through who knew they were here. The owner of the house come to say hello? Eric? There was no one else. Whoever it was, she had to get rid of them, and quickly.

Roland

Roland pulled up outside a stone cottage. He had lost the GPS signal in the last few miles and had to slow down outside each drive he passed to check the house names.