With Sunday approaching, Relf arranged protection for the people they knew might be at risk.
Martin. The Hatherleys. Marris. Anyone Bull had contacted about the cipher, and anyone connected with Michael's enquiries.
Hale remained unaccounted for.
Martin objected to having officers involved in his daily movements. Hatherley wanted to discuss the necessity of it at length.
Relf heard them both, then left the arrangements in place.
"And me?" Eleanor asked.
"You stay in touch. Tell me before you go anywhere."
"Who's doing that for you?"
He looked up from the telephone.
"I'll tell you where I am."
She accepted that and returned to Mercer's file.
The surviving correspondence about his Hong Kong appointment included terms, fees, travel and accommodation.
One letter preceded the rest.
It recommended Mercer as a British specialist with exceptional practical knowledge of maritime smuggling, forged documents and clandestine movement through ports.
The writer was not a Customs official.
He was the managing director of a commercial security company operating across Asia.
Edward Lamb.
Eleanor pointed to the signature.
"Another Lamb."
Relf read the letter.
"We'll check him."
Edward Lamb had died in 2017.
The company still existed under another name. Its ownership led through a Singapore parent company to a trust whose beneficiaries were not identified in the records they had.
The current company secretary was easier to establish.
Helen Lamb, Edward's daughter.
She was fifty-one, born in Hong Kong and educated in Britain. She had qualified as an accountant and returned to Hong Kong in the nineties.
They found no criminal record.
Nor, so far, any connection to ringing.
"Does she work for the same people who hired Mercer?" Eleanor asked.
"That's what we need to establish."
"And what she knows about him."
Relf added her name to the enquiries.
Helen had entered Britain legally through Heathrow before Bull's death.
She had used her British passport and hired a car.
Camera records placed the vehicle in Kent, then East Sussex.
On the Monday Bull died, it was recorded in Rye at 17:48.
Eleanor leaned towards the screen.
"About an hour before the fall."
"Yes."
"Where did it go next?"
"We have nothing until the following morning."
"Where then?"
"Dover."
The record placed her car nearby. It did not tell them whom she had met or where she had spent the night.
There was no hotel booking they had found under Lamb. Her telephone records showed activity in Kent and East Sussex, but did not place her at the church.
"What about now?" Eleanor asked.
Relf checked the latest information.
"London."
He read farther down the page.
"She has another booking."
"For when?"
"Sunday."
"A flight?"
"No."
Eleanor looked at the decoded message beside the keyboard.
SUN 2340
Relf turned the screen towards her.
Helen Lamb had booked a ferry from Dover to Calais.
Departure: 23:40.