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The Sinking City Quid Pro Quo case guide

We’re in deep, continuing our The Sinking City main case guide series with its third case, Quid Pro Quo.

As per usual, spoilers lie ahead: continue at your own will.

Case #2: Lost at Sea | Case #3: Quid Pro Quo | Case #4: Fathers and Sons

  • First, go to the Oakmont Police Station.
    • Violent Crimes
    • Instruments of Crime.
    • Suspects.
  • Using the archives, select the expedition’s fate as evidence, then:
  • This will point you to the Fish Market in The Shells.
  • Go and speak to Anna.
  • She’ll point you to Fish Storage (The Shells, Hawking Lane between Warren Rd and Liberty Rd).
  • Speak to the guard and give him the password from Anna.
  • Kill all the enemies, then inspect all the evidence.
  • Walk through the portal and piece together the timeline:
    • 1: Man checking fish.
    • 2: Man checking the other fish location.
    • 3: Guard on the second floor.
    • 4: Guard throwing the harpoon.
  • Speak to the guard.
  • Speak with Anna at the Fish Market. Betray the guard for (Achievement/Trophy: Brutal Honesty).
  • Head to Oakmont University (Reed Heights). Speak with the man at the locked door to learn of the Department of Medicine.
  • Head there — it’s just down the road — and speak with the man at the counter.
  • Clear the enemies from the basement as the man asks.
  • Inspect everything, and then click the red button near a door a couple times to unlock (Achievement/Trophy: Reanimator). Try to kill the big bad, or just flee like I did.
  • Go the 2nd floor and check all items. Use your Mind’s Eye behind Professor Cavendish’s desk.
  • Head to Oakmont City Hall and use its archives to find Cavendish:
    • Residents
    • Records
    • Advent.
  • Head to find Cavendish’s house (Advent; Michael’s Road, between Carpenter Street and Constitution Street).
  • Examine all clues.
  • Walk through the portal to sort the timeline:
    • 1: “I have something to tell you.”
    • 2: Fighting in the kitchen.
    • 3: Fighting near the front door.
  • Speak to Cavendish when he comes in.
  • Head to your Mind Palace and make a conclusion. I chose the Professor’s side for (Achievement/Trophy: Compliments to the Chef).
  • To side with Cavendish, head back to Fish Storage and speak with the guard to get in (if he’s there, that is).
  • Poison the fish crates.
  • Speak to Cavendish, who is nearby.
  • To go the Fish Market and speak with Fred in the basement.
  • Head to the Throgmorton Manor and speak with Robert to finish the case.
  • I poisoned the fish crates and I spoke to Cavendish once more.

Case closed! Next, Fathers and Sons.

The Sinking City is available on Windows PC, Xbox One and PS4. We reviewed it here.

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Steve Wright

Steve's the owner of this very site and an active games journalist for the past ten years. He's a Canadian-Australian gay gaming geek, ice hockey player and fan. Husband to Matt and cat dad to Wally and Quinn.