The Case Of The Scorpion’s Tail - 1971 - 6/10
AKA - La Coda Dello Scorpione

Good Giallo that plays with conventions and expectations.
Older husband dies in airline disaster, and his young, promiscuous wife inherits a cool million.
She soon draws plenty of attention: police, Interpol, insurance investigator.
And a masked killer who wields a nasty knife.
Multiple locations dance across a jagged, deliberately misleading plot.
Audio commentary with the scriptwriter. In it, he tells how he favored thrillers based on money or revenge, which had to obey reasonable lines. He was not a fan of Argento’s maniacs, where anyone could be guilty in the final reel.