“Which floor’s that on?”

“Sixth.”

“Describe how you get there from the pool.”

“There’s no pool.”

“What do you want?”

“Information about Ascension Island and Quadrant. What they’re doing there; why it’s so sensitive.” She kept her voice steady, as authoritative as possible.

“Who sent you?”

“No one.”

“You’re on your own?”

“Yes.”

“Then you’re really fucked.” He shook his head in amazement. “Turn right again, then in by the leisure center. Stop at the side.”

They waited to see if anyone caught up. She could hear his breath. After a moment Latham got out. She thought he was going to run, but he climbed into the front passenger seat.

“What makes you think I have anything to do with Ascension?”

“You entered a file on the system: Quadrant and Ascension. It was product from Jerry Lau.”

“And what do you know about Jerry Lau?”

“You were running him, then got interested in Ascension—then you disappeared.”

“You need to go back to Vauxhall and forget all this.”

“There are several lives in danger. Jerry Lau’s is one of them.”

“Why? What’s happened?”

“His boat was found with all the crew killed. Lau’s in hiding.”

“Any suggestion who killed them?”

“No.”

“Was the boat searched?”

“Torn apart.”

Latham swore quietly under his breath.

“Tell me exactly what the situation is on Ascension Island,” he said.

“An officer of ours died there. It appeared he hanged himself, but I believe he was killed. He was over there to assist with some GCHQ work, but seems to have stumbled into something more dangerous.”

“On Ascension?”

“Yes.”

This provoked a few seconds’ silence from Latham.

“Is it connected to what’s happening today?”

“What do you mean?”

“For Christ’s sake. Drive.”

He directed her onto a rocky path, through a jumble of allotments, past an old barn and a burnt-out trailer. A sign warned of guard dogs but there was nothing moving in sight, just dilapidated farm buildings and a muddy track.

“Let’s leave the car here.”

She stopped the car and they walked fast, in silence, past empty fields to a shallow wood with an abandoned fridge deep in its wet leaves.

“What was your man over there for?” Latham asked.

“Cable tapping.”

“Purely technical, or security elements?”

“He was assessing security.”

“On the island.”

“Right.”

“My guess is that your officer stumbled into Gemstone.”

“Who’s Gemstone?”

“I’ll tell you what I can. You listen at your own risk.” He checked his watch. “Then I think you’ll see why this isn’t a situation for you to get involved with.”

“Okay.”