Codename: Seabat. The most dangerous submarine ever created. Explosively nuclear and manned by a crew that is officially dead, the Seabat is the most closely guarded military secret in the world. And it has just gone rogue.

Two teenagers get drowned in the river. To come back to life, they have to explore the spirit world and find their purpose and mission in life. Their adventure starts from hell and continues into Shambhala and beyond. Can they come back to life?

Renton, son of scientists, and Eureka, a girl who can't live under the sun, are raised together when very young and become very attached to each other. One day, Eureka is taken away. Powerless at the time, Renton vows to rescue her. He enters the military and is soon is assigned to the Independent Youths Unit 303 of the First Mobile Forces thanks to his exceptional performance alongside his Nirvash, a bio-mechanical armor/control system. Unknown to Renton, lies a plot to extinguish the alien invasion that is currently happening involving not only him, but Eureka too.