When dissolute fisherman Abel Davenport discovers an ancient temple in the deep ocean, he under the influence of a long dead god. In his attempts to restore the god's cult, Abel unleashes a plague of twisted doppelgangers on Arkham. Horrified by the consequences, Davenport realizes that he alone cannot stop the monsters from resurrecting the Ancient One. Sometimes the only way to end one cult is to start another.

In the swirling sewers beneath Arkham, excavators uncover a crystalline formation that hints at dark events from the city's past. As the discovery makes headlines, so too does a series of bizarre murders. With no leads, the Arkham police are always one step behind. Acting on a hunch, down-on-his-luck former journalist Andy Van Nortwick reunites with adventurer Jake Williams and struggling filmmaker Maude Brion to unearth the truth. The trio know of the supernatural horrors that lurk beyond this world, and the reality haunts them.

When Arkham Advertiser reporter Andy van Nortwick receives a mysterious film reel in the mail, with a simple note: "Maude Brion is very much alive!", he steps onto a path which will lead him to the brink of madness. Brion, the famous actress and film director, vanished a year ago on an ill-fated expedition into the Amazon rainforest, delving into the legend of the Spider Queen. Thrilled by the prospect of his big break, Nortwick swings the funds to launch a rescue mission. He gathers a team of explorers and a keen folklorist to bring back Brion and cement his reputation.

Aspiring painter Alden Oakes is invited to join a mysterious art commune in Arkham: the New Colony. When celebrated Spanish surrealist Juan Hugo Balthazarr visits the colony, Alden and the other artists quickly fall under his charismatic spell. Balthazarr throws a string of decadent parties for Arkham’s social elite, conjuring arcane illusions which blur the boundaries between nightmare and reality. Only slowly does Alden come to suspect that Balthazarr’s mock rituals are intended to break through those walls and free what lies beyond. Alden must act, but it might be too late.

On picturesque College Hill in Providence, Rhode Island, an old colonial house has sat empty for decades. No one would consider renting the house with its long history of woes and unexplained deaths. Can a young man and his elderly great-uncle get to the bottom of the unspeakable causes of the house's affliction? Or will their investigation bring them face to face with an enduring evil?