The title is a pun on the word "phobia". The number 4 is in reference to the film's four short stories.
Happiness (Thai title - Ngao/Lonliness; directed by Youngyooth Thongkonthun)
A young woman, stuck in her apartment thanks to the cast on her leg, communicates with the outside world via cell phone and text messages. She begins receiving text messages from a stranger, who seems friendly enough, and there’s no reason for her to read between the lines when he mentions that he is currently dwelling somewhere “cramped.” After sending the mysterious stranger her picture, she asks for one in return and is sent the same picture. When she questions him, he says he is in the picture next to her. A ghostly face is slightly visible next to her smiling face. As she researches recent deaths she discovers that a man died and was buried with a cellphone. She then gets a text saying that he will come to her place now. All of the lights begin to go out and the young woman cries in fear. She is then assaulted by the ghost and is thrown out of the window to her death. We are then shown that the man died while walking across the road, being struck by the taxi that crashes and breaks her leg.
Tit for Tat (Thai title - Yan Sang Tai/Deadly Charm; directed by Paween Purikitpanya)
Imagine a childish payback like writing a joke about your friend's parents on the blackboard. Then imagine a payback of vocational schoolboys who curse people they hate on a deadly charm. Let's see what excruciating pain these curses will bring to the table, and the bloody time is on to kill everyone who face this event.
In The Middle (Thai title - Kon Klang; directed by Banjong Pisanthanakun)
On a remote camping trip through a lonely jungle, four teenagers begin to tell ghost stories to entertain themselves. Eventually, the young men become frightened by their own stories and fight over who gets to sleep in the middle of the tent which they believe, is the safest and most secure spot to sleep...or so they think.
The Last Flight (Thai title - Teaw Bin 244/Flight 244; directed by Parkpoom Wongpoon)
Flight attendant Pim, goes aboard an airliner on a charter flight for the Princess of Khurkistan. What was supposed to be an ordinary flight turns into something tragic when the princess forms an allergic reaction to something she ate. After the royal house of Khurkistan requests that her body be sent back immediately for cremation, Pim (Chermarn Boonyasak) is required to remain on the plane and escort the body - the only passenger - for the return flight.
While the four stories above appear to be isolated, the chronology of the events are: a) Story 3 (In the Middle). One of the teenagers' name is Ter. b) Story 4 (Last Flight). Ter is mentioned as the brother of Pim's colleague and fellow stewardess, Tui (not seen in film) who could not accompany the flight as her brother had drowned. c) Story 1 (Happiness). The girl with the broken leg is seen reading the online news about the Princess's son's death. The princess was there for the funeral. d) Story 2 (Tit for Tat). The image of the curse is the image of the girl with the broken leg who had died with her eyes open.
