The first reply Adam typed was Don't open it.
He stared at the words. Mara had a spare key to his apartment, not his car. Then he remembered the little key in the magnetic box under the rear bumper. She'd been with him when he'd put it there. She'd told him it was a terrible hiding place.
He added, Please. Walk back to the road. Call me from there.
A thin bar crept halfway across the screen and stopped.
"Is she in the water?" Sera asked.
"She's standing beside my car."
"Then why are you looking at the ground?"
He was standing with his toes a few inches from the leaves. He hadn't felt himself move. He stepped back and shoved the phone into his pocket, where it immediately began to feel more important than anything he could see.
Sera picked up a fallen branch. With the blunt end she scratched a line in the dirt, well above the highest leaf the water had reached.
"Stay on this side," she said.
"Why did you bring me here?"
"You asked me to."
"You knew what it could do."
"I knew what my grandmother said it did. She also said I'd get a stye if I watched a dog piss." Sera pressed the branch into the ground until it stood upright. "I thought I'd show you two stones and bring you home before the bread went hard."
Home. The word passed between them so easily that Adam almost let it go.
"How long have you lived up there?"
"In the cottage? Since I was nine."
"By yourself?"
"Since autumn."
He had more questions. There was something about the way she said autumn that made him save them.
✦ ✦ ✦
Three knocks came from below the leaves.
Two close together. One after a pause.
Mara had knocked that way on his bedroom door when they were children. It meant she had something to tell him and didn't want their parents to hear. Once it had meant she'd broken a plate and wanted him to say he'd done it. Once it had meant their father had packed a bag.
He crouched.
"Tell me what you heard," Sera said.
"Her knock."
"Did she say in the message how it sounded?"
"No."
"Then we don't know which of you it's meant for."
She picked up a dry hazel leaf and set it down in the hollow. Nothing happened. She took another and held it out to him.
"Put it where I put mine."
He reached across the line she'd drawn. Before he could set the leaf down, a thread of water came up through the litter and fastened itself to the tip. He let go. The leaf dropped, and the thread fell with it.
Sera drew him back by the loose wool at his elbow. It was such an ordinary thing to do, the little tug on his sleeve, that for half a second he could imagine they'd known each other for years.
Then the phone buzzed again.
His reply was still sitting on the screen with the bar halfway across it. A second message had come in beneath it.
It stopped when I knocked back.
"Oh, Mara."
He said it the way he'd said it when she'd climbed onto the kitchen counter at seven to get a glass. A glass she had broken. A mess he'd helped her sweep up with the dustpan they could barely reach. She'd always wanted to know whether there was somebody on the other side of a door.
He deleted his reply. He typed just her name and tried again. The bar moved a fraction this time. From below the leaves came a sound like someone drawing a breath to speak.
He turned the phone face down against his leg.
"Come back to the cottage with me," Sera said.
"What if she sends something else?"
"You'll read it better by the fire, with hands that can hold it."
He wanted to say it didn't work that way. He could explain cell towers and signal strength, and somewhere in the middle of it he would have to explain how a phone had rung in a hollow in 1726. He followed her up the hill.
✦ ✦ ✦
In the cottage Sera lit a rushlight and took a small book from a shelf. A length of red thread held it shut. She pulled at the knot, then had to use her teeth. Adam put his phone on the table between them. Its screen had gone black again.
"My grandmother kept accounts for three houses," she said. "If somebody owed her a halfpenny, she'd write down which half."
She turned past pages of numbers. There were drawings in the margins. A loaf of bread, a hen, the outline of a child's hand. The finger marks in the paper made Adam think of the thumbprint he'd seen in the garden.
"Here."
She pushed the book toward him. The writing leaned far to the right. He made out the date first. The last day of March, 1694.
Below it were three lines.
He called me by my name from under the ford. I did not answer. When I came to the house my brother was there. He had been there since noon, and our mother had set a place for him.
"Your grandmother's brother came home?"
"She told me about the ford the year before she died. She said he was never found." Sera flattened the page with both hands. "I found this after the burial."
Adam read the lines again. "Did she write anything else about him?"
"There's a page missing."
She tilted the book. A ragged strip ran along the stitching. Near the bottom, in a spot somebody had missed when they tore the page, two words remained. Adam could make out the first. When.
The rushlight bent toward the table.
His phone woke without a sound. The glass showed an incoming call, but there was no name on it now. Only a number.
His own.
Across the table, Sera drew the book closer to the light. The fingers of her left hand stayed on the page. Her right hand moved slowly across the table until it rested beside his, close enough for him to take it if he wanted.
He picked up the phone.
Before he could touch the screen, the call answered itself.
For a moment he heard road noise. A car door chimed. Then he heard himself speak, close enough to the microphone to catch the breath he always took before saying something he hadn't rehearsed.
"Mara," his voice said. "I'm sorry I didn't answer this morning."