Lo Scorpione a Due Code (1982)

Joan Mulligan is waiting in vain for her husband, Arthur Blanc, an Etruscologist who has traveled to Tuscany in search of materials for an exhibition. The woman, who suffers from metapsychic disturbances, "sees" in a nightmare the cave her husband has discovered, where Arthur is mysteriously murdered. She then departs for Italy herself, determined to shed light on her husband's death, and finds herself entangled in a series of other murders that have taken place in the same cemetery—all of which share one same macabre detail. Mike, a secret agent who has fallen in love with her, must uncover the truth behind the intricate mystery. (extended version of Assassinio al Cimitero Etrusco)

Unfortunately the movie Lo Scorpione a Due Code is not yet available on HBO Max.