Allie Fox (Harrison Ford) is an inventor, handyman, and opinionated individualist who is fed up with America's commercialism. He has created an ice machine which makes ice out of fire. He decides to go where he is really needed. He uproots his wife (Helen Mirren), two sons, and twin daughters from their home in rural Massachusetts and takes them to the jungles of Honduras. His eldest son Charlie (River Phoenix) narrates the story.
They settle in a remote clearing called Jeronimo and begin to transform the wilderness into a Yankee Eden. With stupendous energy and a nonstop verbal barrage, Allie leads the natives as crops are planted, houses built, and a huge ice machine constructed.
The troubles begin when Allie tries to awe others with his accomplishments. Traveling to the interior to show some Indians the ice, which melts along the way, he meets three armed outlaws. They later show up at Jeronimo and take over. The nightmarish end to the settlement precipitates Allie's angry descent into madness.
Harrison Ford tries his best to capture Allie's dark side but just doesn't pull it off. In addition, the mystery that usually pervades Peter Weir's films is absent from The Mosquito Coast. Nature is not as potent a force as it should have been in this drama.
On the positive side, Paul Schrader's screenplay vividly conveys how Allie's pride destroys him. The vehemence with which he attacks God for having screwed up creation a fait accompli made apparent in the success of an extremely competitive fundamentalist missionary is a measure of his Faustian hubris. Allie not only wants to start a new world from scratch, he also believes he can do a better job saving it than anyone else. Like many do-gooders, this man's best intentions go awry. In the end, he is destroyed by the monster of egotism.