Mek is the main antagonist, an occultist who seeks to open the gates of Hell. He is a loyal servant of the evil entity and is ultimately confronted and shot by Jake using an ancient flintlock. Before disintegrating, Mek warns Jake about the consequences of shutting the Gates of Hell, indicating that Jake must pass through the gates himself, which means he is destined to be sent to Hell.

Jake travels to Bangkok with his wife Prang and their daughter Loo to spend time with Prang's mother. After a shooting incident in a shopping mall, Jake ends up in an alternate dimension called the Hindrance. His motivation to save his wife and protect his family drives his actions throughout the film, including his confrontation with Mek and his ultimate sacrifice to close the Gates of Hell.

Jake is assisted by a mysterious novice monk who helps him navigate the supernatural challenges and race against time to save his wife and stop Mek from opening the gates of Hell. The monk's guidance is crucial for Jake's journey through the other dimension called the Hindrance.

The ancient flintlock is a weapon passed to Jake by Prang, which he uses to shoot Mek, the evil occultist. The nona metal knife is used by Jake to stab Wichien, another antagonist, who warns Jake that to shut the Gates of Hell, he must pass through them, implying Jake's destined sacrifice. These weapons are key plot devices that enable Jake to confront the supernatural threats.

At the end, Jake chooses to walk through the Gates of Hell to shut them, which means he is sent to the Hindrance (Hell). He sacrifices himself to fix the world, feeling guilty for not saving his family from the demons earlier. Jake promises to find a way back to his family, and Chan, another character, vows to try to find a solution to save him. Jake's journey is portrayed as just beginning as he walks through Hell.