“You’ve lost us the island,” Skinner said, before she could reply. “In due course, we’re going to ascertain what your game has been, but we have a potential war on our hands now and our priority is getting you as far away from this as possible. Put her somewhere secure,” he said to the police.

“There’s a Russian intelligence officer on the island,” Taylor said as the police grabbed her arm again. “That ship is coming to collect them.”

Skinner stared with a mixture of fury and disbelief. “Spare us, Kathryn,” he said. One of the officers flicked a set of handcuffs open.

“Wait,” Mackenzie said.

“The Yantar is on its way to exfiltrate an intelligence officer who’s been living undercover,” Taylor continued. “We’ve known there was hostile penetration of the space defense program on Ascension since last year. But we never got to the bottom of it, did we, Gabriel?”

The chief turned to Skinner. “Is this something you know about?”

Skinner hesitated, but recovered quickly. “This is a distraction. If you like, I can explain exactly ​—”

“Save it.” The chief turned back to the police. “Bring her to the command room.”

Taylor was led to the lifts. The five of them squeezed in and plummeted down four floors beneath the pavement, where she was ushered through a security pod, past thick metal doors, into the tunnels. They must have passed back under Whitehall, under the Cenotaph, into the beginnings of War Command. There were several subterranean checkpoints, then a decontamination area. Two more armed police stood outside double doors signed DEFENCE CRISIS MANAGEMENT CENTRE. At a nod from Mac­kenzie they knocked, turned the handle, and stepped back.

The room was bigger than Taylor expected, centered on a vast table with multiple sockets and fixed phones. Secondary workstations around the edges of the room included some form of communications hub with staff wearing headphones and mics. Thirty or so people in total, a handful in military uniform, most suited. She recognized the chief of defense staff, the head of MI6 military liaison, the secretary of state for defense himself. Screens in each corner showed live satellite maps, one tracing the Yantar as it crossed the South Atlantic, one, disconcertingly, showing the night sky. A monitor on the table linked with the military’s Permanent Joint Headquarters in Northwood, another to a command center with men and women in US military uniforms.

Taylor was ushered to the front.

“This is Kathryn Taylor from our South Atlantic team,” Mackenzie said. “Tell us what you know.”

“I believe the Yantar is on its way to rendezvous with a Russian intelligence officer who’s been operating under deep cover on Ascension Island. His cover’s been blown. The signals blockage on the island is consistent with an exfiltration attempt and probably originates from a portable device operated by the officer himself.”

There was a second as they processed this.