He knelt beside his daughter.
"Listen to me."
She looked up.
"This is our house."
She nodded.
"And the backyard is private."
"I know."
He took her hand.
"Nobody from the HOA gets to come swimming here just because they feel like it."
The girl looked toward the window.
Then whispered, "But she has a key."
The engineer froze.
"What?"
His daughter looked frightened.
He kept his voice gentle.
"Why do you think that?"
She swallowed.
"When I was getting out of Grandma's car, I saw her friend holding keys."
He felt a chill.
"What kind of keys?"
The girl considered.
"A bunch on a ring."
She pointed toward the backyard.
"She put one near the gate."
The engineer remained quiet.
He remembered the camera footage.
The red-haired woman holding something beside the latch.
Then he asked carefully.
"Did you see the gate open?"
His daughter shook her head.
"No."
He nodded.
"Thank you for telling me."
She looked uncertain.
"Am I in trouble?"
His expression softened immediately.
"Of course not."
He pulled her into a hug.
She held him tightly.
For a moment, he felt the ache of missing his wife.
She had always been better at recognizing when their daughter carried worries she could not explain.
He took a breath.
Then whispered, "You did exactly the right thing by telling me."
His daughter looked up.
"Can you make them stop?"
The question struck him harder than he expected.
He had built a career protecting complicated water systems.
He could explain pressures, pumps, circulation patterns, and equipment failures.
He could manage construction contracts worth millions.
He could identify problems in a system other engineers found impossible to understand.
But his daughter was asking something much simpler.
Could he make adults respect the boundary around their home?
He held her hand.
"I'm going to do everything I can."
She nodded.