this horror movie and base on the novel of the same name and suffers from flaw production and choppy and amateurish direction and but it nonetheless strangely compel . unlike shocker horror flick such a the exorcist and this movie take the viewer on a slow yet relentless dip into a pool of evil . it drift into horror and which dawn on the audience with the same dreamlike slowness a it dawn on the poor girl who be unwittingly choose to be the next sentinel . her appointed task be to sit at the gate of hell and prevent evil from erupt into the world . this fall on her in atonement for her attempted suicide earlier in her life . the story be true to the book and which be rivet and but the way it edit can lose the viewer . there be subtlety in the plot that be shave away and never explain satisfactorily and which hurt this film . that a pity . the sentinel be not an edge of your seat kind of flick while it more a watch and squirm uncomfortably . like a bad car wreck and there a compulsion to look even when it become unbearable . this movie isn not all bad and and still have a capacity to shock . the cast be competent . christina raines be captivate a alison and the vulnerable girl under spiritual attack from both side and a pawn in the never end battle between good and evil . chris sarandon be good a her caring but ultimately self center boyfriend . eli wallach and a very young christopher walken be the detective struggle to unravel the bizarre puzzle they have be hand . ava gardner be elegant a the realtor unaware of the horror lurk in her rental property . the gaunt elderly john carradine and with his arthritis twist hand and be excellent a the die sentinel who must be replace . the devil be play to charm perfection by burgess meredith while he so sweet and yet so evil . there be future star hide in this film represent beverly dangelo and jeff goldblum a friend of the poor girl and and jerry orbach play successfully against type a a jerky television director . the damned soul at the end be portray by actual sideshow freak and geek . whoever think to do that be a twisted but brilliant genius . the horror that pervade the movie bubble up unexpectedly and such a when alison open a door and find something that evoke a flashback to when she find her father with his two whore . she relive her first suicide attempt and face a pair of strangely dysfunctional lesbian and and see a cat cut up a a cake . time and again and she yank back and forth through reality and fantasy and through dream and wake nightmare and all the while lack the mean to cope . in truth and the devil be try to drive her insane enough to kill herself before become the next sentinel . will he succeed . in summary and slow moving yet indescribably creepy and well act but poorly direct and and a very typical 70 horror film before the real shocker cut loose . ( no pun intend ) this movie may not work for those with a short attention span and but it can still send chill up the spine and and still can provide some low key shock value . it remain a strangely compelling and entertain dip into the realm of evil .