The lead chopper disintegrated in a ball of fire.

Marcus stared in disbelief as parts of the fuselage fell to the earth. Then antiaircraft fire erupted below them, and the pilots took emergency evasive action. The Super Stallion lurched left, then right. The pilots fought to gain altitude and get out of range of whoever was firing at them. They had been flying at about ten thousand feet. Now they were racing for the ceiling —about eighteen thousand feet, give or take.

Marcus couldn’t believe what was happening. Charlie Company had run this route a hundred times before. It had always been secure. But then he saw the second helicopter, the one directly in front of them, take several hits. Black smoke started pouring out of its engine. The chopper careened to the left. Her pilots were rapidly losing control and altitude. It quickly became clear she was going down —with a United States senator on board.

For the moment, Marcus’s chopper kept climbing at a rate of about twenty-five hundred feet per minute. But Marcus had no illusions. They were no longer headed for the ceiling. Their mission had radically changed. They were supposed to be protecting Senator Dayton. That meant they had to follow the ailing chopper.

Anticipating a sudden and very rapid descent, Marcus tightened his shoulder harness, then reached over and tightened Annie Stewart’s. Everyone else followed suit, holding on for their lives as the Sikorsky began diving for the deck.

They landed hard on a narrow outcropping on the side of a mountain. The civilians screamed as the landing gear collapsed and they skidded toward the edge of the cliff. Fortunately, they ground to a halt with ten or fifteen yards to spare. But they had no time to lose. The helicopter carrying the senator had crashed on a rocky slope about two hundred yards ahead and below them. Marcus could see smoke pouring out of the cabin, along with some of its occupants. He had no idea whether it had been the Taliban or al Qaeda operatives who had fired upon the three choppers. But whoever it was, surely they had seen the results. They had to know the Americans were on the ground, which meant they’d be racing toward them and radioing for reinforcements as they did, the billowing black smoke acting like a beacon and providing precise coordinates.

Sergeant McDermott moved fast. Pushing aside the civilians —most of whom were in shock or nearly so —he heaved open the side door and jumped out. He motioned his men to follow and everyone else, including the pilots, to stay put. He ordered Nick Vinetti —the sniper —to set up an overwatch position. His job was to take out any hostile forces that might approach from any direction. At the same time, McDermott ordered Pete Hwang —the medic —to scramble down the mountainside with Marcus and provide aid, medical or otherwise, for those in the senator’s chopper. Meanwhile, he said, he would work the radios and call for assistance.

Marcus and Pete did as ordered. When they reached the crash site, they were horrified at what they found. Both the pilot and copilot had been killed immediately upon impact. Four of the dozen Marines on the chopper had also been killed. Two more were severely wounded. The senator himself was wounded in the leg and bleeding profusely. His chief of staff, the political officer from the U.S. Embassy in Kabul, and a senior public affairs officer were badly shaken up but physically had only minor cuts and contusions. Pete immediately put a tourniquet on the senator’s leg, then turned his attention to the two Marines. The others set up a defensive perimeter while Marcus radioed a situation report back to McDermott.

“Sir, permission to move these people up to your location?” Marcus asked, explaining that the fire inside the crumpled fuselage was out of control and risked setting off the fuel tanks in short order.

“Permission granted,” came the response. “Bring the senator first.”

Marcus ordered the able-bodied civilians to follow him back up the mountain to the working chopper as he slung Senator Dayton over his shoulders in a fireman’s carry and led the way. When they reached the others, Marcus set the senator inside the chopper, then scrambled back down the slope to help Pete, only to find that one of the most severely wounded Marines had just died.

That’s when the first crackle of gunfire echoed through the canyon. Marcus spun around, M4 at the ready. He spotted two rebels moving across the ridge to their south, both of them firing AK-47s. He took aim but before he could pull the trigger, he heard two sharp cracks in rapid succession. He turned to see Nick Vinetti reloading his M40 bolt-action sniper rifle. Beaten to the punch, Marcus turned back to see two lifeless bodies crashing down the rocky slope. They were dressed like Taliban. From this distance Marcus couldn’t positively identify them, but it didn’t matter. Whoever they were, there were surely more to follow.

Marcus thanked Nick over the radio, then scanned for more hostiles. But Pete needed help.

“Get this one back to the other chopper,” the medic said as he injected one of the badly wounded Marines, now writhing in pain, with another dose of morphine. “Tell Sarge we need to get him to Kandahar immediately along with the senator.”

“No can do,” Marcus replied. “Sarge says there’s a sandstorm over Kandahar. Nothing’s taking off or landing right now, and they’re not sure how long it’ll be till it lifts. They’re sending backup from Kabul, but they’re at least an hour out.”

“Then another hour back to Kabul?” Pete said. “No way —this guy has lost too much blood. He can’t wait that long. Tell Sarge they need to head back to Kabul immediately.”

“Roger that,” Marcus replied, then heaved the Marine over his shoulders and started working his way back up the mountain.

He’d climbed about halfway back to McDermott and the civilians when he heard a high-pitched whistle coming from his right. He turned just in time to see the contrail of an RPG slicing through the air. He followed the arc until he saw the rocket slam into the only working helicopter they still had. The Sikorsky erupted in a huge fireball, raining metal and rock from the sky. Marcus set down the Marine and covered him until the worst of it was over. He turned around and thought about climbing back down when, below them on a winding dirt road, he spotted two pickup trucks filled with cheering jihadists.

Suddenly there was a flash of light and then came another RPG. Stunned, Marcus watched as it hit the chopper below him, killing most of the Marines positioned nearby.