John Groberg, a farm kid from Idaho, crosses an ocean to become a missionary in the remote and exotic Kingdom of Tonga during the 1950's, leaving behind a loving family and the true love of his life, Jean Sabin. Through letters and musings across the sky, John shares his adventures with "the girl back home," and her letters buoy up his spirits in difficult times. John must struggle to overcome language barriers, physical hardship and deep-rooted suspicion to earn the trust and love of the Tongan people he has come to serve. Throughout his adventure-filled three years on the islands, he discovers friends and wisdom in the most unlikely places, changing his life forever.