Every seven years, an island appears off the empire's southern coast for exactly thirty days, then vanishes. It's on no official chart. The imperial navy has tried to reach it four times and failed — ships lose direction, compasses spin, crews forget why they sailed. Baroness Sola Miren's late husband captained the last expedition. He came back wrong. Couldn't sleep, couldn't speak about what he saw, wasted away in a year. Before he died, he drew a single map — not of the island, but of something *inside* it — and gave it to Sola with one instruction: burn it. She didn't. Now the island is surfacing again, and a disgraced naval commander named Phelan, court-martialed for refusing to fire on a civilian vessel, is the only captain willing to sail. He needs funding. She has her husband's fortune and the only map in existence. The arrangement is simple — she finances the voyage, he captains the ship, and they split whatever they find. But the map doesn't match anything they encounter on the island. It matches what the island encounters in *them*. Every person on the crew starts seeing something different, and the map changes in Sola's hands each night, as if it's drawing not the land but the person holding it.