The salt storage code in The Sinking City 2 is Roman numerals I, IV, IX, and XVI, which correspond to the numbers 1, 4, 9, and 16. Once you understand what these represent, you can press the matching squares to unlock the door.
To solve the puzzle properly, you’ll need three notes: the “16 Punishments of a Sailor” note found on the large brass wall plaque in the Bar, the “Instructions to Sybil” note located just before the Old Shop with the Ward, and the “Warning for Sybil” note in the Jeweler’s area.
The “Instructions to Sybil” note lists four punishments, which you can cross-reference with the “16 Punishments of a Sailor” note to find the correct numbers:
– Confined to ship (I) – 1
– Deprived of beer (IV) – 4
– Tarred and feathered (IX) – 9
– Keelhauled (XVI) – 16
To open the door, press the squares with these Roman numerals in order: I, IV, IX, XVI.
Inside, you’ll find a woman turned into Dream Essence that you can smash for upgrade points, a note about a surprise in the safe, and the Pyre’s Squid Barrel—a grenade launcher upgrade that staggers multiple enemies caught in the blast.