Although Bianca LaBelle, star of the wildly popular silent movie serial The Adventures of Bianca Dangereuse, and Rudolph Valentino, the greatest screen idol of all time, have been friends for years, in the summer of 1926, they are making their first picture together, a steamy romance called Grand Obsession. One evening after dinner at Bianca's fabulous Beverly Hills estate, a troubled Rudy confesses that he has received anonymous death threats. In a matter of days, filming comes to an abrupt halt when Rudy falls deathly ill. Could it be poison? As Rudy lies dying, Bianca promises him that she will find out who is responsible. Was it one of his many lovers? A delusional fan? Or perhaps Rudy ran afoul of a mobster whose name Bianca knows all too well? She calls on P.I. Ted Oliver to help her investigate the end of what had seemed to be the charmed life of Valentino.
