They found the witness three days later.
A woman walking her dog had stopped in the churchyard to adjust its lead. From where she stood, she had heard two voices in the tower. One had called out something she could not make out. The other had answered.
"Did you hear what they said?" Relf asked.
"Not the words. Just the voices."
"How many?"
"Two. One higher up. One below."
"Could you tell whether they were arguing?"
"No."
"Did you hear anything else?"
"A bell, I think. Not ringing. Moving."
She had not stayed. She had finished adjusting the lead and continued her walk.
"That gives him a reason to be there."
"And a reason for the marks on the floor."
"Yes."
She looked at her account of the tower reconstruction.
"We've been imagining Bull calling down the missing letters, Marris understanding them and deciding to kill him."
"That's one possibility."
"But Marris might not have understood any of it."
"No."
"He might simply have done what Bull asked."
"And afterwards lied about being there."
"Because he'd helped cause a death."
Relf was quiet for a moment.
"He disposed of the boots."
"That fits panic too."
"It does."
Eleanor turned back to the witness's words.
"'Again' doesn't tell us whether the next pull was deliberate or a mistake."
"No."
"We need to know what they were saying to each other."
"I've asked for everything recovered from Bull's telephone to be reviewed."
She put down the notebook.
"Do you still think Marris killed him?"
"I think Marris has a great deal to explain."
"That isn't what I asked."
"I know."
She waited, but he offered no firmer answer.
"I'll ring you tomorrow," he said.
After the call, Eleanor left the notebook open beside the lamp. In the margin beneath the witness's account, she wrote:
What did Bull ask him to do?