Archivists cataloging physical records this week uncovered the original acquisition file for Hull 581 — the decommissioned research submarine that has sat in the museum's waterfront berth longer than most Lexicon City residents have been alive. The intake manifest was filed roughly four decades ago. The donor: anonymous. Transfer: private waterway permit, no vessel identification beyond its registry designation. Prior classification: deep-water survey vessel, origin unknown.

The museum's director called it "the first real lead we've had on where it came from."

That's not even the most interesting part.

As part of the restoration review that followed, the museum has opened Hull 581's lower compartments to the public for the first time since the vessel arrived. What's down there — beyond the original instrument panels and survey equipment still mounted to the walls — hasn't been fully cataloged yet. Archivists are still working through it.