Atri's last order that was given to her by the capsule was to go to Eden. However, Natsuki and the rest are perplexed by the incomplete set of instructions and don’t know where to even start looking. They haphazardly search for the location in the ever-expansive sea and find themselves in a hopeless situation with no progress. But the clue Ririka finds reminds Natsuki of a specific memory.