Thomas Jane’s character, David Drayton, spent the movie finding himself as the lone voice of reason among increasing amounts of mob mentality, violence, and panic. Whether it was him dealing with the increasingly violent religious sect that emerged among the survivors, who began sacrificing people to appease the monsters or the people who straight up refused to believe that anything had gone wrong, eventually walking willingly into the mist and meeting their doom. Drayton tries his best to act reasonably among such escalating foolishness, but at every turn, his decisions go wrong and cost people their lives.
This pattern of futility comes to a head during the movie’s shocking and impactful ending sequence. The ending, which differs from the ending of Stephen King’s original novel, features Drayton and a few others finally having escaped from the grocery store, finding shelter in a car. With only four bullets left in his gun, the group accepts their impending fates, and they decide to die by suicide rather than be victims of the horrors around them. As the fifth man with four bullets, Drayton kills the four other survivors, including his young son, and then awaits his fate. Not long after he makes this agonizing choice, the army arrives on the scene, and it appears the day has been saved, but not before he made an unnecessary sacrifice.
The divisive ending has been praised by King himself. It’s the ultimate example of Drayton making what appears to be a noble choice, putting others out of his misery and sacrificing himself, only to have the rug swept from under him, realizing they were mere minutes away from rescue. It’s a final gut punch that cements the theme of the fruitlessness of rationality in crisis.