When struggling filmmaker Dean moves into an Airbnb, he quickly discovers that he is not alone. Marcel, an adorable one-inch-tall shell, already lives there with his grandmother Connie and their pet lint, Alan. Once part of a sprawling community of shells, Marcel and Connie live alone as the sole survivors of a mysterious tragedy. Taken with his unlikely new friend, Dean starts filming Marcel and his grandmother, igniting a meteoric rise to internet fame that changes their lives forever.