In a small California town during World War II, an eight-year-old boy named Pepper, who is undersized for his age, shares a close bond with his loving father. When his father is drafted into the war, Pepper feels utterly lost and helpless. At church, he hears a sermon about faith moving mountains and takes it literally, believing that if he has enough faith, he can bring his father back. Determined, Pepper embarks on a mission to accomplish tasks given to him by the local priest, Father Oliver, who provides him with a list resembling the "works of mercy" from the Bible. The tasks involve various acts of kindness and bravery, including befriending Hashimoto, an elderly Japanese man ostracized by the community due to anti-Japanese sentiments from the war.

As Pepper persists in completing his tasks, he faces skepticism and bullying from others who doubt his efforts. Nevertheless, his unwavering faith and newfound friendship with Hashimoto begin to change those around him. The townspeople's attitudes start to shift as they witness Pepper's dedication and the genuine bond that develops between him and Hashimoto. Whether or not Pepper's ultimate wish to bring his father home will be fulfilled remains uncertain, leaving the community and Pepper himself to grapple with themes of hope, belief, and perseverance in times of deep personal and collective hardship.