In Bucks County, Pennsylvania, Colleen Hess(Patricia Kalember), the wife of local priest Reverend Graham Hess(Mel Gibson), dies a horrific death in a traffic accident. After the accident, Graham denounces his faith and his vocation to work full time on his farm. His brother, Merrill(Joaquin Phoenix), moves into the farmhouse to assist his brother in looking after Graham's two children, asthmatic son Morgan(Rory Culkin) and daughter Bo(Abigail Breslin). Six months after the accident, crop circles appear in Graham's corn field. They initially speculate that local trouble-making youth could be the culprits. However they learn that theirs is only one of a number of crop circles made simultaneously worldwide. In addition, animals have been acting erratically. Morgan and Bo seem to have a better sense of what is happening than the adults. Based on other evidence, the family slowly begins to believe that the crop circles are only one of many signs being sent by extraterrestrials. Not knowing if the extraterrestrials are friendly or not, the Hesses take extreme precautions to protect themselves. Graham also begins to believe that nothing that happens is by chance, and that everything has a reason.