Based on Christopher Barzak's novel "One For Sorrow," Jamie Marks Is Dead relates the life of Adam in the wake of classmate Jamie Marks' death, a death which follows shortly after bullying incidents.
After Adam witnesses the ghost of Jamie, Adam wants to investigate who murdered Jamie. Adam's friend Gracie discourages his desire to unravel the mystery that becomes more and more psychological.
Some character motivations puzzle viewers in the middle. For instance, why does Gracie discourage Adam's sleuthing? What do Adam and Jamie want from each other? Some of it is explained by a very satisfying if melancholy conclusion; some of it remains a mystery. Also, the film make plain how Jamie, an attractive young man, had slipped into high school with no friends. One suspects poor socialization, but it isn't much demonstrated in his afterlife.
It's well worth watching, though. Several scenes are beautifully shot and composed, and it will leave you pondering questions of life and death.