Haifuri: The legend of the SS Zephyr

Yokosuka 2026. Captain Akeno Misaki and her crew are on a joint patrol with the Taiwanese and Vietnamese coast guards at the Sino-Japanese-Taiwanese border as part of Task Force 84, a multinational maritime peacekeeping force fighting against Taiwanese and Indonesian pirates that have been attacking foreing merchant vessels and oil tankers.
One day, while escorting a South Korean oil tanker, a mysterious dot appears on the radar which alerts all navy vessels. Assuming it to be a pirate mothership, Akeno decides to pursue the vessel and arrest its crew without any bloodshed.
As soon as they approach though, the entire crew discovers that the mysterious vessel is the SS Zephyr, a Dutch oil tanker that disappeared in 1976 without a trace.
Alarmed by this new discovery, the Blue Mermaids contact captain John Zervas, the commander of the Maritime Research and Intervention Center, a multinational non-profit associasion tasked with the sole purpose of keeping the seas clean.
As soon as the first team of researchers arrives though, strange things begin to happen on board the old vessel, from diseases to mysterious deaths which causes John to delcare the ship off limits.
Things get even more strange with the arrival of lieutenant Christiaan van Herk, an officer sent by the Dutch navy, seemingly to observe the situation.

What is really happening to the SS Zephyr? And what's the point of the lieutenant's presence there? Could this be part of something bigger?

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