Supermodel Alison Parker (Cristina Raines) moves into a nice Brooklyn Heights apartment, and finds out the tenant on the top floor of her building is a blind priest. Pretty soon, she starts having strange physical problems, trouble sleeping, and flashbacks to her attempted suicide.

Not to be confused with the [[Series/TheSentinel 1990s TV show]], or the 2006 movie starring Creator/MichaelDouglas and Creator/KieferSutherland.

!!This movie contains examples of:

* BigBad: [[spoiler: Charles Chazen, heavily implied to be {{Satan}} himself.]]
* BrokenBird: Alison has issues due to her father being abusive, which caused her to lose her faith and attempt suicide.
* CatScare
* ChristianityIsCatholic: The Catholic Church is responsible for [[spoiler: preventing the door to Hell from being opened.]] Alison is also a non-practicing Catholic at the beginning.
* DeadAllAlong: [[spoiler: The other residents of Alison's apartment building. Used to great effect when Alison talks with Michael at the end.]]
* [[spoiler: DownerEnding: Alison, much to her own dismay, becomes the next sentinel and now watches over the gate, as the brownstone is torn down and made into a modern apartment complex, with she ''still'' guards]].
* EvilAllAlong: [[spoiler: Michael, who had his wife murdered so that he could be with Alison.]]
* EyeScream: While fighting off the corpse of [[spoiler: her dead father]], Alison cuts his eye with a knife.
* FanDisservice: A flashback shows a young Alison walking in on a threesome her elderly father is having with two obese women.
* HornyDevils
* HotAsHell: The apartment is a ''gateway'' to Hell
* LegionsOfHell: "I am one of the Legion of the Dead."
* PeekABooCorpse: [[spoiler: Alison's undead father.]]
* ReligionIsMagic / ReligiousHorror The film plays with this, enforcing the usage of ChristianityIsCatholic along with the fact Catholic priests keep the gate closed.
* ThoseTwoGuys: Detectives Gatz and Rizzo.
* YouCantFightFate: [[spoiler: Alison ends up becoming the next sentinel, despite trying to escape this fate.]]