Characters & Suspects
Who's who aboard the Mortuga submarine — the investigators, the victim and the eight suspects with motives and alibis.
The investigators
| Character | Role | Notes | | --- | --- | --- | | Detective Grimoire | Player protagonist | Hired by Sinthia Seafoam to investigate the locked-room murder. He breaks the case by interrogating suspects, collecting clues and reconstructing the truth. | | Sally Spears | Grimoire's partner | Returns from previous games; provides hints and comic commentary throughout the investigation. |
The victim
| Character | Role | Notes | | --- | --- | --- | | Captain Magnus Mortuga | Murder victim | Found dead in the locked Illusion Theatre beside an ancient stone cauldron. Former captain of the Mortuga submarine. |
The suspects
- Sinthia Seafoam — Acting captain. She hired Grimoire to investigate. Taking command so quickly after the captain's death makes her a primary suspect. Linked to the Inn Deeds.
- Symmetry — Illusionist / magician's daughter. Her magic act equipment is found in the Illusion Theatre. Linked to the Golden Locket.
- Zephyr — Dream Chamber occupant. Associated with the Dream Helmet and perfume bottles.
- Dirk — Engineer / bunk room occupant. Owns the cellphone used to light the Bilge.
- J.D. Wirman — Author / bunk room occupant. Owns the typewriter; wrote the novel Hex of the Helmsmen.
- Gripp — Engine Room worker. Knows the submarine's movements; needs to be questioned repeatedly.
- Mariana Moon — Cargo Hold / performer. Hides a pipe-shaped dictaphone with secret recordings.
- Tadpole — Airlock Grotto diver. Provides the birthday clue needed to unlock the Pocketbook.
Sources: ninewiki.com walkthrough, 2026-07-17; grindnstrat.com puzzle solutions, 2026-07-18; themermaidmask.wiki, 2026-07-18.