Ethan took his dipper net and bucket from the bow-side roof. He’d write Polly a note about the tree-house boy while they had hot chocolate. He would tell her everything he had remembered. Then they could go to the pond. If he and Polly were really lucky they might see a dragonfly sitting on the reeds, shining blue and green in the sunshine.

Ethan stepped down off the bow plank and on to the towpath. He walked quickly; he had to meet Polly.

“Ethan!” called Dad.

Dad was behind him on the towpath. He was loading up his tool bag ready for work.

He turned to Dad and held up his net. I’m off to the pond.

“I need your help,” said Dad.

Ethan pointed down the canal to Polly. He didn’t want to go with Dad. He could see Polly waiting outside Moon’s End. She was smiling and waving. He waved back.

“It’s all right, I’ll talk to her, son.” Dad headed down the canal to Moon’s End. Polly walked along the bank to meet Dad. Dad spoke to Polly and Polly nodded.

“Off we go,” said Dad when he got back. “Polly’s not upset. She can join us another day. I thought we’d spend some time just the two of us.”

Ethan leant the dipper net against the side of Deity. He looked back at Polly and she waved again. Dad started walking down the canal path to the clearing where the van was parked and Ethan followed.

They climbed in. Dad turned the key and the van lurched up the lane. At the crossroads, he didn’t turn left to town like Mum always did. He turned right. Soon they were twisting through tiny lanes. There weren’t any houses or buildings, just flat fields with spindly hedges. Dad nodded to the bag of liquorice allsorts on the dashboard, but he didn’t say where they were going or what kind of job it was. Dad’s overall smelt earthy. That was how he had always smelt, even when Ethan was little.

They turned up a long track with tall trees on either side. The van juddered over the gravel, then stopped outside a big grey house.

“Out you get,” said Dad, nodding to the door.

It looked like a gardener hadn’t visited the house in years. The grass on the lawn was up to Ethan’s knees. It was good that Dad had got this job, but it would take him a long time by himself.

Ethan followed Dad to the back of the van. “Take this,” Dad said.

The tool bag was heavy. Dad took a shovel and a bag of peat from the van. “This way,” he said.

They walked away from the house to a row of flower beds. They didn’t have any flowers, just a few shrivelled-up shrubs. “Here we are.” Dad pointed to a circle-shaped flower bed.

Ethan dropped the tool bag on the ground. Dad dropped the bag of peat and lifted his shovel and sliced into the earth. Then he started digging, churning up the soil with the sharp blade.

Little lumps of earth flew up and landed at Ethan’s feet. He kicked at them with the toe of his trainer. What was Polly doing now?

Dad stopped digging and turned around.

“Have you got the flask, Ethan?”

Ethan bent down and looked in the tool bag. He shook his head.

Dad laid his shovel on the ground. He came over and searched the bag. “For God’s sake!” Dad kicked the bag of peat. Thud: the sound echoed in Ethan’s chest. In a second, he wasn’t in the tatty garden. He was standing on the canal bank near the train tracks. Dad was facing the big boy with the blue coat and ginger hair. Then the big boy was stumbling back, falling on to the towpath by the weeping willow. His head fell on the concrete last. Thud.

Had Dad hit the boy? Hit him so hard that he fell and knocked his head? Was that the bit of the memory Ethan had forgotten? It couldn’t be. Could it? It didn’t make sense. There must be another explanation. Another reason why the boy fell. But he’d remembered Dad being angry with the boy. He remembered him falling back.

“Ethan?”

Then he and Dad were back at the tatty garden with the empty flower beds.

Dad sighed. “I forgot it. I’m sorry. It was my fault, son,” he said.

Dad was quiet for a while. He didn’t pick up the shovel. Instead he reached into his pocket and held out a little blue rectangle.

“I found it yesterday in the lounge. I’m glad you’re using it.”

It was Ethan’s notebook. It was open at his message to Polly.

I don’t know why I stopped.
I can’t remember.

Dad passed Ethan the notebook.

“You don’t know why you stopped speaking, do you?” Dad said quietly, his eyes glistening.

Ethan looked past the flower beds to the spindly trees in the distance. His breath felt tight; Dad never spoke much about his voice. Not these days. He used to talk about it all the time.

“Ethan?”

He looked at Dad and shook his head. Dad let out a big breath. “Didn’t think so. Sometimes it’s best not to remember, Ethan. Sometimes it’s best to leave the past behind.”

Dad stepped towards him and laid a hand on his shoulder. Ethan began to feel dizzy. He and Dad weren’t in the garden now; they were back near the tree house and the vandal boy was lying under the weeping willow not moving and Dad was looking down on Ethan, with his hands on Ethan’s shoulders and his face all pink, his eyes wide with fear.

“Go! Run home.” That’s what Dad had told him to do that day.

Then Ethan was back in the overgrown garden and there wasn’t a boy on the ground and when he looked up Dad’s eyes weren’t full of fear, just grey and empty, but Ethan still felt dizzy.

Dad took his hand off Ethan’s shoulder. He crouched down and looked at him. “You’ve got to be careful in life, Ethan,” he said. “Can’t let the past take over, like weeds in a flower bed.”

Ethan nodded and tried to listen to Dad.

“If you come out with me at weekends, I’ll train you up.”

Dad stood up. He opened the bag of peat and lifted a stack of flowerpots from the tool bag. He reached into the pocket of his overall and brought out a packet of seeds. He lined the pots up in a neat row. Ethan watched him.

Dad put a handful of peat into each flowerpot and sprinkled in some seeds. He filled the pots with more peat. He bent over them and pressed down on them gently with his fingers. “Here, you have a go.”

Ethan knelt down next to a flowerpot. He started to squash the peaty soil. He didn’t like the way it stuck to his fingertips, how it got under his fingernails and made them black. He tried to press down hard just like Dad, but his hands were shaky.

He tried to think of all the good things Dad did for him, like singing him to sleep while playing his guitar, Dad’s voice slow and soft and beautiful. Or making little wooden narrowboats that he could float on the canal. But he still couldn’t forget that boy, falling back with a thud, lying out on the concrete.

Why didn’t Dad want him to remember?