The Sinking City 2 Investigation System Explained

Frogwares built its reputation on detective games, and The Sinking City 2 brings that DNA back — but only if you want it. Investigation is fully optional. You can complete the main rescue mission without pinning every note to the detective board. Players who engage, however, earn talent points, shortcuts, supplies, and deeper Lovecraftian context.

This guide explains how the system differs from The Sinking City (2019), where a single missing clue could halt the campaign.

Opening the detective board

Press C on PC (Investigation) to open the board overlay. Readable objects glow or display a prompt when Calvin can extract a clue. Pick up letters, photographs, ritual residues, and audio logs, then assign them to the board as notes.

Drag lines between related notes to form connections. Valid links highlight and often reward a talent point immediately. Invalid links simply fail — no punishment, no soft-lock.

Optional vs mandatory clues

Main story objectives mark critical interactables with standard quest prompts. Everything else is bonus content:

• Side cases — self-contained mysteries in hospitals, mansions, and speakeasies
• Environmental secrets — hidden rooms behind bookcase switches or flooded basements
• Lore documents — codex entries that flesh out Arkham families and cult history

Missing optional clues never prevents you from raising a floodgate, entering a district, or finishing the demo. At worst you skip a stash of ammo or an alternate skiff route.

Rewards for thorough detectives

Confirmed and previewed bonuses include:

• Talent points for correct note connections
• Alternate paths that bypass combat-heavy streets
• Crafting materials in investigator-only rooms
• Weapon attachments tied to optional missions like Holloway Manor
• Codex lore for Cthulhu Mythos fans

The demo teaches this with the Gate Switchboard puzzle: linking fuses and wires grants a point even if you already knew the solution.

How many clues exist?

Developers stated that large map zones can hide 20–40 clues each, but only a subset is needed to resolve any given optional case. Approach investigation like a buffet: take what interests you, ignore genres you dislike (occult chemistry, family trees, etc.).

Investigation vs combat pacing

Safe rooms let you review the board without time pressure. Mid-combat, the board closes — you cannot pause a fight to deduce. Establish a habit: after clearing an area, return to the nearest safe room, connect new notes, spend talent points, then push forward.

Tips for players who hated TSC1 gates

• If deduction frustrates you, follow main quest markers and only connect notes when the game highlights both pieces automatically.
• Use audio logs while backtracking — they play while you move, saving downtime.
• Consult Demo Walkthrough for mandatory puzzle steps without spoiling optional cases.

Post-launch expansion

Full Arkham will add multi-step cases spanning districts. We will catalog case names, reward tables, and missable clues after release in this article and on Updates.

Pair investigation reading with Arkham Map for district context and Getting Started for control bindings.

Comparison with Sherlock Holmes titles

Frogwares’ detective heritage shows in note quality and voice acting, but The Sinking City 2 never forces courtroom deductions. Think of investigation as an optional mastery track — similar to collectible compendiums in action RPGs.

Speedrun and minimal-clue routes

Speedrunners can ignore the board entirely while routing safe-room saves and ammo caches. Any% categories will likely skip optional cases unless talent points prove necessary for later skips — we will document emerging strats after launch.