Every 10-year-old boy loves the lake - unless that boy is Patrick Turkel. Despite his father's encouragement, he avoids the water because he promised his mother he would. Yet, when he finds a wayward toy submarine washed ashore, it's enough to instill in him a longing for adventure.

Years later, Patrick is a grocery clerk still living at home. His father long gone, Patrick supports and cares for his ill mother. Patrick's friends Karen and Joe have a hard time wresting him from work and home, even to celebrate his birthday. And when they finally do, tragedy strikes.

Patrick suddenly finds himself without responsibility and a life unfulfilled. He makes a daring plan to pursue his childhood dream of sailing a submarine across Lake Michigan. Karen and Joe - who always wished Patrick would pursue his ambitions - are now doing anything to hold him back.