The plot revolves around Agumon, Gaomon and Lalamon, whose partners are put into an eternal sleep, along with the rest of the humans, because of a mysterious thorn that spread throughout the city. After saving Rhythm, a Digimon in the form of a young girl, they learn from her that the thorns are the work of an Ultimate Digimon, named Argomon, and the four set out for his castle to confront him.