Dr. Daniel Poe Schreber (psychiatrist) appears in the 1998 Sci Fi/Noir, Dark City. While exact details of the character's background are not revealed, he appears to have skills and interests in scientific exploration and laboratory testing beyond his profession as a psychiatrist.
Schreber reports that he was chosen by The Strangers, a group of "endangered extraterrestrial parasites with a collective consciousness who are experimenting with humans to analyze the nature versus nurture concept of their human hosts in order to survive." (sc:wikipedia)
the dominating alien race controlling and experimenting on the city, due to his aptitude for understanding the human mind, and the building blocks of memory and personality. Some time before the film's start and presumably at the onset of the City's existence and its experiments, Schreber is shown being forced to erase his own memories to become only a tool in the hands of The Strangers.
Throughout the course of the film, Schreber is shown traversing between the the human world of the city and the Stranger's domain underneath, never seeming to completely belong in either place. It is presumed that he has no personal interactions with the city's inhabitants. Schreber is shown preparing the memory templates necessary by The Strangers to change the identities of the subjects of their nightly experiments. He also accompanies as small group of The Strangers into the city during the nightly Tuning to personally inject the memory imprints into their recipients.
At the beginning of the film, Schreber fails to completely imprint the film's protagonist, John Murdoch, with his intended memory template, leaving the man without memories or a proper sense of his own identity. The doctor flees the scene of the imprint, but places a phone call to the man shortly afterward to warn him of the Strangers. Schreber makes several attempts to contact Murdoch throughout the rest of the film, claiming the desire to help him. He unsuccessfully attempts to force Murdoch to inject himself with a memory template at gunpoint, insisting that it contains "All the answers (he's) been looking for", but his actual intentions and loyalties are questionable until shortly before the film's climax.
When Murdoch is eventually captured by The Strangers, Schreber is ordered to imprint the man with a special syringe that contains the Stranger's collective memories, in order to make Murdoch one of Them. However, Schreber secretly retrieves the syringe that he had made to give Murdoch his answers, and switches the syringes at the last minute. The resulting injection creates a complete lifetime of memories for Murdoch in which he is taught and trained by Schreber to use his Tuning abilities and take over the Stranger's machines. As a result of Schreber's aid, Murdoch is able to save himself, destroy the Strangers, and take ownership of the city.
At the movie's close, Schreber is shown on the streets of the city, alone, but a free man, and he disappears into the darkness with a satisfied smile.
Originally imagined as an older man, when Kiefer Sutherland took interest in the character, it was decided that being younger and "having his whole life ahead of him" would both make the character more dynamic and give Schreber more incentive to assist the movie's protagonist.
The inspiration for Schreber's strange, halting speech patterns was taken from famous character actor, Peter Lorre. Sutherland states this was an attempt to impress upon the audience how long Schreber had spent without normal human interaction and proper conversation.
The name Daniel Schreber is the same as that of a man who wrote a book titled "Memoirs of My Nervous Illness" during the heights of a period in which he was institutionalized for schizophrenia and a desire to experience sex as a woman. The book has become a standard reading for many psychiatrists and psychologists, and many of the theories of both Sigmund Freud and Carl Gustav Jung were based on it (Freud never actually met Schreber, though). "Dark City" borrows heavily from the concept of "fleetingly-improvised men" which are found within Schreber's "Memoirs".
In the Director's Cut commentary by writers Lem Dobbs and David Goyer, Schreber is compared to "The Jew in the concentration camp that sells out and helps the Nazis." However, it is left to the viewer to decide if Schreber indeed sold out long ago and is only helping Murdoch through a sense of guilt or a change of heart, or if the character's limp, perpetual hunch of pain and scarred and twisted face indicate a much darker reason and coercion behind his betrayal his own kind.
Sutherland on forgetting which leg he was supposed to limp with on Dark City:
"Alex [Proyas] looks at me and says, like I'm an idiot, "It's your left one!" But you've got to remember, he's watching a lot of what's going on a monitor, which inverts everything, so then he's like "No, wait, it's your right one! No one figured on an actor who was so stupid he couldn't remember which leg was supposed to be limping. I just had a brain freeze."