There was a pause while the lamps flickered again and Janvier turned blankly. “She says: "Imperative I board you. Matter of national importance. Please observe radio silence."

The lamp on the conning tower of the submarine was still. “What shall I reply, sir?” Janvier said.

Duclos raised the binoculars to his eyes for a moment then took them down. “What can you reply? If it’s important enough for them to send a blasted sub after us, then it’s important. Signal: "Come aboard."“ He grimaced at the quartermaster. “I was looking forward to all that sun. My rheumatism’s been killing me lately. Let’s hope we don’t have to go into Brest.”

The quartermaster shrugged. “Stranger things are happening in the Republic these days.”

“Which republic?” Duclos demanded sardonically. “Stand to all hands and get a ladder over the side.”

The quartermaster moved away and Janvier lowered the lamp. “They thank us for our co-operation.”

“Do they, now?” Duclos observed. “Let’s hope they aren’t wasting our time. Stop all engines.”

Janvier moved into the wheelhouse and Duclos took out his pipe and filled it from a worn leather pouch, watching the submarine as he did so. The forward hatch was opened and a large yellow dinghy hauled out and inflated. As the freighter started to slow, the two vessels drifted together until finally the gap had narrowed to no more than twenty or thirty yards.

The submarine commander climbed down the ladder from the conning tower and paused at the bottom, watching the half-dozen sailors working on the dinghy. He was slim and rather boyish in his reefer jacket and rubber boots, and the peaked cap was tilted rakishly to one side. He glanced up at Duclos, smiled and waved, then walked along the hull and stepped down into the dinghy.

He was followed by half a dozen sailors, most of whom carried sub-machine-guns slung across their backs. Four of them paddled the boat across the narrow strip of water towards the ladder that had been dropped over the side of the Kontoro. Two sailors, still standing by the forward hatch of the submarine, carefully paid out a connecting line.