After your last battle at sea, the thought of going sailing makes your stomach churn. But luckily the water around File Island are generally peaceful and all the villains living there are under surveillance.
The Armadillomon village in the rocks near the Ocean is on your way home, so thinking about those mighty cliffs makes you sigh with relief. Arriving there, you are welcomed by the Digimon to participate in their Digivolve Festival, where the oldest of them are Digivolving to Ankylomons. No other Digimon are allowed to participate, but your fame bought you and your team front seats!
Just as the bonfires were lit and the sun set beyond the horizon, the Digimon took their place in a long line, moving in a mesmerizing dance. Just as the dance was getting faster, an earthquake made you all tumbling around. Among the panic, an Armadillomon rushes to you and says to take a look at the sea. Trying to contain your fear, you take a look and see a horde of Seahomons firing their beams at the cliffs you are standing on!
A particular large one shouted: "You will all face our wrath when Sabmarimon will tear down your precious cliffs' base on the ocean's floor!" Not knowing what it's talking about, you insist that the panicked Armadillomon gives you an explanation. Fighting its tears, it admits that the Digimon that fail to Digivolve are thrown in the Ocean in order to live as Seahomons, and that their leader - Sabmarimon, must be an Armadillomon that rebelled against the tradition and swore to take down the whole village.
Although you have to sort this out, for the time being you have to dive down with your team and face the wrathful Sabmarimon!