Q:Generate a question that has the following answer: Walter Lambert for the following movie plot: After seven years, Tricia, a pregnant woman who lives alone in the Los Angeles valley, is finally ready to accept that her missing husband Daniel will not return. As she prepares to declare him dead in absentia, her sister Callie, a former addict, comes to stay with her. Together, they work to obtain Daniel's death certificate and find a new apartment for Tricia. As the date approaches, Tricia has terrifying nightmares and hallucinations about Daniel that her psychiatrist interprets as stress and guilt. While jogging, Callie runs into a gaunt man in a tunnel who seems shocked that she can see him. He begs her to contact his son, but she runs off. Later, she returns with food and leaves it in the tunnel. When Callie discovers a pile of small metal objects on their doorstop, she assumes they were left there by the man in the tunnel, and she places them at the tunnel entrance. A man walking by advises her not to do so and deposits a trash bag in the same spot. She later finds the pile of metal objects on her bed. Detective Mallory, who has been investigating Daniel's disappearance, responds to the call and chastises the women for leaving their door unlocked in a dangerous neighborhood. Callie secretly relapses into drug use, and Tricia signs her husband's death certificate. As Tricia steps out on a date with Mallory, a bloody and barefoot Daniel suddenly appears in front of their apartment and collapses. At the hospital, doctors diagnose Daniel as severely malnourished, dehydrated, and physically abused. Daniel seems surprised that others can see him and can only explain that he was "underneath". Tricia contacts his parents, and he returns home, where he acts strangely and urinates in fear of the sight of the tunnel. Mallory and his partner, Detective Lonergan, attempt to interrogate Daniel, but he does not respond. Later, Tricia breaks down and strikes Daniel, begging him to explain his disappearance, but he still does not respond. Mallory comes by, and he and Tricia talk in his car. Mallory pledges his...
A:
Who is the man Callie saw in the tunnel?