The Tainted Cup (2024) is the first book of the Shadow of the Leviathan series by American author Robert Jackson Bennett. A sequel to The Tainted Cup, A Drop of Corruption, will be released in 2025.

Bennett, known for his speculative fiction and elaborate world-building, made his debut in 2010 with Mr. Shivers, which won the Shirley Jackson Award for outstanding achievement in psychological suspense, horror, or dark fantasy; he is also the author of Divine Cities (2014-2017) and Founders (2018-2022) trilogies.

This book references the Del Ray/Penguin Random House 2024 e-book edition.

Content Warning: The source material depicts ableism and violence.

Plot Summary

In Daretana, a small town on the edge of the Empire of Khanum, 20-year-old Dinios “Din” Col, who has magically fueled eidetic memory, is the assistant to investigator Anagosa “Ana” Dolabra. When Commander Taqtasa Blas, a high-ranking military officer, dies in the secure house of the rich Haza family of a tree erupting from his body, Din is sent to survey the crime scene. The house staff fears this is a contagion, or a magical enhancement gone awry.

Ana uses Din’s detailed report to determine that the Hazas’ groundskeeper, Uxos, killed Commander Blas using dappleglass, which causes plants to grow inside bodies. Uxos confesses that he was paid to let in a mysterious assassin who poisoned Blas’s bathwater. Life briefly returns to normal until an enormous oceanic titan breaches the sea wall that holds its kind at bay, causing chaos.

Ana and Din are summoned to Talagray, the city nearest the sea wall, to investigate. Ten sea wall Engineers erupted with trees, like Blas. Four of them were stationed on the walls during the dappleglass eruption, which caused the weak spot that let the titan break through. In Talagray, Din meets the local investigative team: investigator Tuwey Uhad, Engineer Valiki Kalista, war hero Tazi Miljin, and Ionia Nusis, an Apothetikal, or military officer who works with magical augmentations of organic materials. All the dead Engineers were all part of a secret group of officers under Haza patronage, a legal but unethical system. The only Engineer left alive is Kiz Jolgalgan, who, Ana deduces, is the poisoner of both his peers and of Blas.

Blas’s secretary, Rona Aristan, is found dead. Her nearby safe house shows that she traveled repeatedly to several Empire cantons (or districts) and possessed an ornate key that looks like it is designed to open a magical lock but is actually a cure for dappleglass. Ana keeps Aristan’s death a secret, intending to use the body’s “discovery” to check for corruption among the investigative group. They all pass her test.

Din travels with Captain Kepheus Strovi, a flirty Legion officer, to investigate a miller of fernpaper—a common building material affected by dappleglass. The miller, who has been killed in the same way as Aristan, provided a great deal of fernpaper to the Haza family. In response, Fayazi Haza, a member of the powerful family, reports that her father, Kaygi Haza, has also died of dappleglass poisoning to deflect responsibility.

Din receives permission to visit the Haza estate, where he finds a large swath of dead grass where Jolgalgan hid before the poisonings. Din checks the Hazas’ correspondence system; he is not a proficient reader but manages to recreate the shapes of the letters using his memory. When Ana interrogates the investigative team, Nusis reports that she was present during the “Oypat crisis,” when an entire canton was lost to dappleglass contagion. They attempted to make a cure, but it could not be confirmed effective in time.

Din and Miljin seek an Oypati crackler, or someone magically augmented with extreme strength; they believe that this person helped Jolgalgan access the Haza estate. They discover the crackler just as he dies of dappleglass; nearby, Jolgalgan herself has also been killed by dappleglass. Despite this apparently neat conclusion, Ana feels that the case is not over. However, another titan approaches the sea wall, so their investigation pauses for a banquet to bless those going to fight the titan, including Strovi. Din and Strovi admit their mutual attraction, but do not have time to act on it. Nusis is dead; her killer searched her safe for the magical key Din found at Aristan’s house.

Ana summons everyone involved in the case and reveals that Jolgalgan only intended to kill Blas and Kaygi for their role in the Oypat crisis: blocking the dappleglass cure to render Oypati land unusable, thus raising the value of their own land. Jolgalgan, who is Oypati, chose dappleglass as her murder weapon for this reason. The 10 Engineers died by accidental contagion after they shared a pitcher with Kaygi; the breach of the wall was thus an accident. Fayazi, acting on orders from the scions of the Haza clan, allowed a twitch, or someone augmented for speed, to come to Talagray to kill witnesses, including Aristan. Ana identifies one of Fayazi’s supposed servants as the Twitch. As bells chime announcing the arrival of a titan at the walls, the twitch nearly escapes, but falls prey to a dappleglass trap that Ana rigged.

After the titan is killed, Ana reveals that Uhad was the third poisoner, as he hated the corruption of the Hazas; Uhad intended to spend his retirement killing more of the privileged clan members. Strovi and Din enjoy their limited time together, as Strovi remains stationed at Talagray, while Din plans to travel to the Inner Empire with Ana to continue their work.