Cultists in bloody ritual garb are an unremarkable sight on the streets alongside fishermen, average townsfolk, refugees from the destruction of nearby Innsmouth, the destitute and desperate, and well-heeled members of the upper class.

Six months prior to the events of the game, Oakmont was inundated by a mysterious flood of supernatural origin that has submerged many of its streets and cut it off from the mainland.

The Flood brought with it a dark force that pushes its terrified citizens toward madness, along with a plague of otherworldly monsters called Wylebeasts, and the struggling city is on the brink of collapse.

[10][11][9] Charles Reed, a former U.S. Navy diver and World War I veteran turned private investigator, travels from Boston to Oakmont at the invitation of Professor Johannes van der Berg to discover the cause of the nightmarish visions that have been plaguing him since surviving the wreck of the USS Cyclops.

While pursuing his primary investigation, Reed addresses several other cases which embroil him in the politics and conspiratorial machinations of the power players of Oakmont.

Reed discovers the attempted killer is Brutus's son, Graham, an army veteran who wishes to turn the family away from crime and use their fortune to help the needy.

Graham has made a devil's bargain with the Redemption Church, a cult that worships Shub-Niggurath, and used their magic to create a docile duplicate of Brutus.

The Blackwoods, one of Oakmont's grand families, raised Ebernote in the belief that he was one of the Chosen Few, people who are granted visions by a mystical property called the Seed of the Dreamer.

Every few centuries, when the stars are right, the Chosen are drawn to Oakmont, where the last survivor has the power to unseal the sunken temple of Cthygonnaar and release Cthylla, the secret daughter of Cthulhu and Idh-yaa as well as the source of the Flood, the Wylebeasts, and the nightmares.

Van der Berg reveals he brought Reed to Oakmont and prompted him to become immersed in its underbelly because he wished to persuade him of humanity's worthlessness and impel him to fulfill the prophecy.

Reed is faced with a choice, leading to one of three endings: When planning The Sinking City, developer Frogwares envisioned the open-world setting of Oakmont as a densely-built urban area that was two kilometers square.

The areas of the town designated for flooding also used unique assets in their generation, such as silt, seaweed, and barnacles, to make them stand out in their districts.

[16][17][18] Frogwares Community Manager Sergey Oganesyan explained that the decision to delay the game was made in order to avoid a crowded release window and allow for additional polishing time.

[25] This resulted in The Sinking City being delisted from Steam, the Epic Games Store, and the Xbox One and PlayStation 4 digital storefronts on August 25, 2020 pending the resolution of Frogwares' legal dispute with Bigben.

[32][33][34] Reviewers generally praised the game's writing, worldbuilding, and the lack of hand-holding in finding and drawing conclusions from clues to solve cases, but criticized the combat as slow and frustrating, and noted multiple technical issues, such as overly long loading times and screen-tearing.