AKA Seven Blood Stained Orchids - excellent stylish Giallo from the master of the genre.
Some-one is slaughtering young women (just for a change) but what lifts this is the logic of the plot and the way the focus changes away from the police to the central characters.
Giana (Glas) is the third victim but survives and a plot is hatched with her husband Mario (Sabato) to pretend the killer succeeded so they can follow up the clues and unmask him.
She used to own a hotel and 7 women stayed there in a single week - the two previous victims and herself so they know who the killer will target - can they be saved while working out why they have been selected.
The plot become ever more complicated with an veritible ocean of red herrings and blind alleys but in the end it makes logical sense as its proceeds to its finale.
Shot mainly in Rome it makes great use of the locations with a solid supporting cast - it tends to suffer a bit from comparisons with Argento but its a very fine example of the genre - 4/5