"Thorin, we’ll never make it", Balin told the dwarven Prince in exasperation. "Some of us might. Lead him to the forges. We kill the dragon. If this is to end in fire, then we will all burn together", he told them before telling them the plan of splitting up. 

He leads Bilbo and Balin to the forges. "This way!", that was until the dragon came upon them from behind. "Flee! Flee! Run for your lives! There is nowhere to hide", he taunted with a growl before Ori, Dori and Bombur come behind him. "Behind you!" "Come on!", it seemed to have worked since Smaug's attention was towards them. While distracted by them, Dwalin and Nori come up behind him from another direction. "Hey, you! Here!", the creature now turns to attack them, but Dwalin and Nori make a run for it. That was until he notices Bifur and Gloin running in another direction, and he goes after them instead, unleashing a cloud of fire as they fled.