Once again, Musashi has encounter Ultraman Cosmos. Now Ultraman Cosmos has gained some new modes to defeat Scropis. Musashi has joined Team Sea to save the Blue Area. But there is mysterious evil monster, Sandros, who wants to destroy the Earth. Now it is up Musashi and Ultraman Cosmos to defeat Sandros and who’s the other Ultraman?
The organization Mighty Jack is formed to combat the criminal syndicate known as "Q", and are given a large array of advanced weapons, chief among them being a high-tech submarine. Harold Hatari is abducted by Q, and Mighty Jack is dispatched to rescue him. Hatari is interrogated and threatened with blinding lights, but the Mighty Jack crew rescue him in the nick of time. Later, Q is discovered to be using "hot ice" (water that remains solid at room temperature) to create weapons and a secret ocean base disguised as an iceberg (though it's not precisely clear how hot ice could be a major world threat). Q then attempts to take over the Mighty Jack sub.
