A young woman (Hayley Mills) misses her train and is forced to hitchhike. After a misadventure with a horny truck driver who wants her to pay a "fare", she is picked up by a handsome but mysterious stranger (Simon Ward) who may just have escaped from an asylum for the criminally insane. This is a familiar role for Hayley Mills that she had basically performed several times before: the pretty dolly bird who meets a slimy creep that she is nevertheless somewhat sexually attracted to (except that her usual co-star Hywel Bennet is replaced here by Simon Ward). When she played this role back in "Twisted Nerve", however, she was still coming off her wholesome Disney image, and was appealing, but also pretty two-dimensional. In "Endless Night" she played a troubled heiress and had little more of a rounded character and performance. In this movie the back-story of her character, revealed in flashbacks where she is orphaned in a car accident and sent to live with a lecherous uncle, might make her even more troubled than the sinister young man who picks her up. (There is in fact a great twist at the end here that I don't want to reveal).
Ironically, Mills first played this "endangered innocent" role as a child actress way back even before Disney in 1959's "Tiger Bay" (where she plays a pre-pubescent girl who steals a gun and befriends a murderer). It took her this long, in what was basically to be her last film, to get back to the acting and fully developed roles in which she first started. It was revealed years later that Mills had been offered, and nearly accepted, the title role in Stanley Kubrick's "Lolita". And while that notorious role ruined the career (and perhaps life) of the actress who eventually took it (Sue Lyon), it might have actually been better for Mills than all the saccharine, cloying Disney movies she got typecast in.
This is pretty much Mills show all the way. Ward is good but pretty functional. It's generally well directed by journeyman director Sid Hayers ("Assault", "Circus of Horror", "Revenge"). Sterling Hayden shows up in a cameo as an eccentric old coot (and his character's harmless flirtations with Mills have some unintentional sexual tension given that in real life she had recently married a man about Hayden's age). And, oh yes, and for those of you whose minds are in the gutter (along with mine), Mills also has some nice nude scenes. Good luck finding this as it is undeservedly very obscure today, but it's definitely recommended.