Adrienne Saunders is happily married to her art dealer husband , Jack . They have a daughter named Mary . Adrienne hears from a friend that she thought she saw Jack in town when he claimed to be on an out of town business trip . Adrienne confronts him , but he denies being in town , and their lives continue . Soon after a museum curator is mysteriously murdered , and a relic that Jack bought for the museum is revealed to be a fake . Jack is placed under suspicion , and then Adrienne receives word from the police that Jack perished in a car accident . In trying to wrap up Jack 's affairs , Adrienne begins to suspect that her husband had switched identities with a high school classmate , Frank Sullivan . When she sees a high school yearbook picture of her husband attributed to Sullivan , she is convinced . She tracks down a relative of Saunders , who confirms that Frank and Jack were inseparable in high school . After Jack died , the relative never saw Frank again . She explained that Frank 's father was an alcoholic and that his mother worked as a toll booth operator . She directs Adrienne to Frank 's mother , who lives in a rundown apartment in Brooklyn . Frank 's mother bitterly receives the news that she has a granddaughter , telling Adrienne that Frank was always selfish and that he never looked in on her . A stalker lurks at Adrienne 's loft . He comes in to Adrienne 's bed while she is asleep and caresses her . He watches Mary , who is spooked by the man in her room at night . 
How does the yearbook confirm Adrienne's doubt about her husband's identity?
Adrienne doubts that her husband Jack had switched identities with high school classmate, Frank Sullivan which she confirms after seeing the yearbook