Janet (Jennie Linden) experiences disturbing nightmares and is sent home from her exclusive school, supposedly to recover. It doesn't take long to discover why she’s troubled – a few years prior, her mother experienced a severe mental breakdown and killed her father. Now Janet worries that she might be facing a similar condition, and unfortunately, things don't improve for her at home either. Freddie Francis directs Jimmy Sangster's story effectively, capturing the essence of Hammer films but with greater refinement. The film relies heavily on psychological suspense, unfolding with subtlety (accompanied by a fitting score from Don Banks), which pulls you further into the narrative. The performances are solid rather than exceptional, allowing the storyline to take center stage. The script moves along at a good pace, contributing to an engaging mystery that maintains tension throughout its 80-minute length.

Source on TMDB