Normally in movies, the possibility of time travel is packaged in strange metal boxes, telephone wires, electrified helmets or specialized vehicles.
If a character were to claim he'd traveled through time without such apparatuses, surely it would seem like a farce.
This is why we're never sure if Jack Starks, Adrien Brody's character in "The Jacket," is developing visions of the future in his imagination, or if his experiences are something of the paranormal.
We are first introduced to Jack in 1991, as a U.S. soldier during the Gulf War in Iraq.
Miraculously surviving a gunshot wound through his head, Jack returns home to Vermont suffering from amnesia and delusions.
When he is brought to court soon after on charges of murdering a police officer in the state, Jack only vaguely remembers two things from the day in question: a mother and child whose broken-down car he fixed and a man who picked him up while he was hitchhiking. Jack is found not guilty of the murder by reason of insanity and is sent to a psychiatric hospital.
Where "The Jacket" goes from here warrants both praise and criticism.
Jack is given heavy doses of experimental drugs at the hospital, so anything shown to us by Director John Maybury is highly interpretive. Either Jack is hallucinating and we see his visions, or we believe his claims of sanity and take what we see at face value.
When Jack is bound in a straightjacket and thrown into a morgue cabinet - with all good intentions, according to the hospital staff - he closes his eyes to find himself in 2007.
Here he meets Jackie (Keira Knightley), the grown-up version of the little girl who watched him fix her mother's car before his murder trial.
Part of the film's development is problematic, as Jack and Jackie become friends, then lovers, during his time in the morgue cabinet.
For one thing, if we are to believe in the time travel idea, Jackie seems strangely wooed by Jack's bizarre-sounding claims.
When they first meet, she is cautious of him and then kicks him out of her house immediately after he confesses his identity.
The next time they meet, she acts as if she's been anxiously awaiting his arrival, despite their previous negative encounter. After only one afternoon together - even as she's with a man who jumps at every noise and says he's from 1992 - she's eager to have sex with him.
What makes their relationship even more curious is afterward he visits Jackie in real time, with the assistance of a hospital worker (Jennifer Jason Leigh). And before him is the woman who just dragged him upstairs to bed, only now, she's probably 8 years old.
Despite these issues, "The Jacket" remains intriguing for several reasons.
The first is the concept of time and how Jack's time travel experiences come full-circle in the film.
For instance, in one scene from 2007, he encounters his doctor, Thomas Becker (Kris Kristofferson). Jack tells Thomas who he is, and how he's one of many patients who haunts Thomas.
In response, Thomas tells Jack how he died in '92, and that his last words were the names of Thomas' old patients. Back into the past, as Jack feels he is about to die, he utters those same words to his doctor; this time, we're not sure if it's because he just found out he was supposed to, or he was going to all along.
