Dean looked where his brother pointed. Seeing the state of the car, was when Dean hurried out to the car with Sam, a pistol in hand with the safety on. When they were checking what could be seen, Dean had to wonder what had happened and who was in the car. Were they okay? Where did they go? It was when Dean's attention was on the same coughing that Sam heard. The older ran toward the warehouse and inside it, safety off and watching his surroundings for anything and everything while following the sound of the coughing. Silver bullets in the clip and ready to go. He hadn't thought twice that Sam had his back as he had gone in the building despite what maybe within.