There were six Wrens on the map. Eleanor found two more online. Relf added a ninth after telephoning a man who, he said, knew the Marsh.
Wren Cottage, Wren Farm, Wren's Dyke. Little Wren. A public house that had closed years ago.
Eleanor worked through them while Relf drove. None gave her a reason to choose it over the others.
"What did your man suggest?"
"Wren's Cut. Old drainage channel."
She searched for it. Nothing.
"Whereabouts?"
"South of here. Parts of it were filled in when they changed the drainage."
She enlarged the map on her phone, following the thin blue lines between fields.
"If it's gone, why use it as a meeting place?"
"I said parts."
The road narrowed. Relf slowed for a bend, and the headlights swept over a gate with a length of chain hanging from it. Beyond the gate she could see nothing. She had spent the afternoon looking across fields that seemed to go on for miles; now she could barely make out the edge of the road.
"Bull might have known the old name," she said.
"He was a historian."
"So might whoever sent him the message."
Relf watched the road.
At eight forty-six he pulled into a gateway and stopped the engine.
Eleanor looked up from her phone. "Are we here?"
"No. I need to make some calls."
He took out his mobile and checked the signal.
"We've got until eleven fifteen," she said.
"We've got a time written in a notebook. We don't yet know what it means."
"You think it's worth going, though."
"Yes."
The answer left her with nothing to argue against. She put her phone down.
Relf's first call was mostly listening. He gave the name Wren's Cut, then asked the person at the other end to repeat something. On the second he got out of the car. Eleanor heard a few words before he closed the door.
She brought up the message again.
WED 2315 / 4 / WREN
She had taken Wren to mean a place because they needed somewhere to go. It could still be a surname, or the name of a boat.
And the four?
She tried people, packages, boats. There was no way to choose. She was fitting possibilities to a number.
Outside, Relf walked a few paces along the verge with his phone against his ear. She lowered her window. Water trickled in the ditch beside the gateway, but she could not see it.
He returned to the car and made a third call. This time he asked about access.
At nine twelve he put the phone away.
"There was a landing place," he said.
"At Wren's Cut?"
"Where it joined another channel."
"Was?"
"The man I spoke to remembers it. He doesn't know what condition it's in now."
"Can we get there?"
"He's given me directions."
Relf started the engine. Eleanor closed her map. For the past hour she had wanted him to settle on somewhere; now that he had, she wished she knew more about it.
"An old landing place on the Marsh," she said. "You can see why Bull would have been interested."
Relf checked the road before pulling out.
"Don't say Doctor Syn."
"I wasn't going to."
He glanced at her.
"All right. But I wasn't going to say it aloud."
He eased the car out of the gateway. She watched for a turning, although she had no idea which one they needed.
After they had passed the next bend, a vehicle pulled out of a side road behind them. It paused at the junction until their tail-lights had disappeared, then turned in the opposite direction.