"Show me," he said.
Outside the rain had thinned to a drizzle. Jethro carried a lantern and Rosamund another. They went along the landward foot of the Barrier Bank, squelching through mud to the ankle, with the huge dark wall of the bank rising on their left and the river invisible beyond it, only heard: a deep continuous hush like wind in a forest. Fifty yards below the wheel house Jethro stopped and lowered his lantern.
The boil was a little round welling in the turf, perhaps a foot across, bubbling softly like a pot on a low fire. The water that came up out of it was the colour of strong tea. Around it the grass lay flat in a widening fan of silt.
Ivo knelt and put his hand in it. It was very cold. Through his fingers he felt the fine grit of sand moving.
"How many men can you get?" he said.
"Tonight? Ten. Twelve. There's the Danby lads and the Hollises up the drove—"
"Get them all. Every man and every boy. Every sack in the engine house and the coal store. Spades. Clay from the dyke side. Stakes, hurdles, anything that will hold earth." Jethro was already moving. "Rosamund."
It was the first time he had used her name. He did not notice he had done it until later.
"Yes."
"I can't see." He said it flatly, without looking at her. "Not in this. Not past the lantern. I can tell them what to do, but I can't see where the water's going, or whether it's working, or whether there's another one starting further down. I need you to see it for me."
There was the shortest pause.