“What is it now?” the president asked, standing up as they came in.

“Sir, please come with us,” the shift supervisor said. He and a second agent crossed behind the office’s famous Resolute desk and did something neither had ever done before. They laid their hands on the commander in chief to move him forcibly from the room.

The president’s secretary rose to her feet as they passed through reception. “What’s going on? What’s happened now?”

“Stay where you are,” a third agent told her, then ran ahead to clear the way. Word had already begun to circulate through the West Wing. The building was going into lockdown. Nobody was allowed in or out. Except, of course, for the president and First Lady.

“Command, Torchwood is on the move,” the agent radioed ahead.

“Tucson as well,” a voice came back. A separate protective detail was simultaneously escorting Mrs. Coyle down from the residence. “We’re proceeding to the South Lawn.”

“Would somebody please tell me what’s happening!” the president ordered anyone who would listen.

“There’s been an incident, sir. I don’t know the details. You’ll be briefed on Marine One” was all the lead agent would — or maybe could — tell him.

The tight scrum moved without stopping, back down to ground level, where they crossed into the White House and then out again, through the door obscured under the South Portico stairs.

Outside, it was obvious that the entire White House Complex had been shut down. Armed Capitol Police officers were lined up along Executive Avenue on either side, and there was no dress blue marine to meet them as the Sea King white-top helicopter descended onto the lawn.

As soon as it touched down, the chopper’s front hatchway opened. The stairs were lowered to the ground.

Only then was the president escorted the rest of the way across the grass, at the center of a fast-moving ten-man human shield.

Two passengers were already waiting on board — another breach of protocol. FBI Director Burns and the president’s counterterrorism adviser, Norma Tiefel, stood up as Coyle came into the main cabin.

Mrs. Coyle boarded with her escort just a few seconds behind the president, and they all took their seats.

Four of the Secret Service detail stayed with them. Once the hatch had closed and Marine One was on its way, they continued to the rear cabin, leaving the president with his advisers.

“Tell me what’s happened, Ron,” the president commanded Director Burns. “Tell me everything, right now.” Regina sat next to him, clutching his hand. How much were they capable of taking at this point?

“Sir, I’m sorry to tell you that Secretary Cho and three of his staff were just killed in an explosion.”

“Oh my God. Martin Cho.”

“An attack on his motorcade, to be precise,” Burns went on. “Presumably Al Ayla, but we can’t say for sure. However, it is consistent with one particular stream of intelligence we’ve received.”

“What do you mean? What kind of intelligence?” the president asked.