What if Luther had taken 2 seconds to pick up the Colt before going after Sam?
Sam's POV
Sam and Dean jumped out of the Impala and ran to the edge of the woods where they knew their dad was negotiating with vampires. As soon as they arrived at the top of the hill where they could see the road, they saw their father being thrown into his truck. Dean looked at Sam and nodded. Sam watched as Dean shot his crossbow twice and then as they had agreed, Sam ran down with his machete to behead the fallen vampires.
When Sam reached the bottom of the hill, concentrating on the vampires Dean had hit, he was met with an incredible force and knocked to the ground. He closed his eyes as the wind was knocked out of him. When he opened them, he saw the head vampire reaching down for him.
"No," he said, putting out his arms to fend him off. The vampire just knocked them away, and lifted Sam to his feet by his jacket. Sam felt the vampire's powerful arm encircle his neck, cutting off much of his air. He reached up and grabbed the vampire's arm, trying to pull it off, but it didn't budge He felt himself swinging around and was greeted by the sight of Dean spinning around to face them, after having picked up the machete that had gone flying out of Sam's hands when the vampire struck him down. If Sam had been capable, he would have sighed a breath of relief. But it would have been premature anyway.
"Don't, or I'll break his neck," the vampire threatened.
Sam saw Dean freeze. He saw the helpless look in Dean's eyes and knew then and there that there was nothing Dean could do to save him. And he certainly couldn't do anything. Just getting the occasional breath was a challenge. He was going to be killed by this vampire.
"Drop the blade," the vampire commanded next.
"Don't do it, Dean," Sam thought. If Dean dropped that blade, not only was he dead, but Dean and his dad as well. He was gratified when Dean didn't do it. Just kept looking at the vampire in defiance.
Then he felt the vampire tightening his grasp on his neck and lifting him slightly off the ground. Sam let out a pained grunt and then everything went black.