The fog was not drifting quickly. Jimmy took out 6 spare bullets and loaded them into the 1875. With the aid of Heart Eye, he located 6 slightly larger white dots. In just over a second, all 6 larger white dots disappeared after being hit by the bullets, and the smaller white dots nearby vanished too.
The fog suddenly became much fainter. Previously drifting toward Jimmy, it dissipated into a larger mass of fog after the white dots disappeared, and within Heart Eye, only a faint, fog-like form could be seen drifting toward the nearby forest.
Jimmy only had 6 spare bullets for the 1875, because the chances of encountering such entities were really too low, so he hadn't prepared many. Now that he had emptied two rounds, he could only put them away, switch to the Python in hand, take another 6 bullets from his pocket, close the car door, and chase after it.