After returning home from the Vietnam War, veteran Jacob Singer struggles to maintain his sanity. Plagued by hallucinations and flashbacks, Singer rapidly falls apart as the world and people around him morph and twist into disturbing images. His girlfriend, Jezzie, and ex-wife, Sarah, try to help, but to little avail. Even Singer's chiropractor friend, Louis, fails to reach him as he descends into madness.
A mix up on her first day of work sends Shane to the Dead Letter Office, where a group of quirky characters led by Oliver try to deliver the undeliverable. Though Shane wants out of this strange detail, she can't help but get caught up in the story of one misdirected letter mailed by a dying young woman to the man she was falling in love with. As circumstances around the letter get more complicated, Shane and the group break all the rules to see the letter delivered and justice done.