A Drop of Corruption

A Drop of Corruption (2025) is the second book of the Ana and Din Mysteries series by American author Robert Jackson Bennett, following 2024’s The Tainted Cup. The Tainted Cup is a finalist for the 2025 Hugo Awards, in the Best Novel category, which grants prizes for significant accomplishments in science fiction and fantasy. Bennett’s works are known for their elaborate world-building and speculative elements.

This guide references the 2025 hardcover edition by Del Ray.

Content Warning: The source material and guide feature depictions of ableism, substance use, graphic violence, sexual content, illness, enslavement, cursing, and discusses “madness,” used in its literary sense.

Plot Summary

Signum Dinios “Din” Kol arrives in Yarrowdale, capital city of the Kingdom of Yarrow, which is under the partial control of the Empire of Khanum but is not officially part of the Empire. Din works for the Imperial Iudex, the arm of the military charged with solving crimes and enacting justice. Din is an “engraver,” or someone enhanced by the Empire’s technologies—called “augmentations”—to have eidetic memory. He meets Signum Tira Malo, an Apoth (or person augmented to have superior senses) who leads him to the partial remains of Immunis Mineti Sujedo, a Treasury officer who was tasked with negotiating with the Yarrow king. Sujedo apparently vanished weeks prior from his locked room (something that Din later learns is the work of Sunus Pyktis, the novel’s primary antagonist, who impersonated Sujedo while in Yarrowdale).

Din puzzles over the seemingly impossible disappearance. He is confronted by a creditor who demands predatory repayment rates for Din’s father’s debts. This leads Din to live on very little money and hinders his long-term plan to transfer to the Legion, an Iyalet (or military department) that he sees as far more effective than the Iudex.

Din’s boss, Immunis Anagosa “Ana” Dolabra, explains that Yarrow has a particular political situation. It is eight years away from the end of a century-long plan to adopt Yarrow into the Empire, and the current king of Yarrow does not wish to give up his nominal independence. In the intervening decades, the Empire has benefitted from Yarrow’s access to sea routes untroubled by the vast leviathans—also called titans—that attack the shoreline of the Empire. This access led the Empire to choose Yarrow as the site of the Shroud, a secretive place where the leviathans’ bodies are dissected and turned into the grafts and augmentations that the Empire uses, in turn, to fight the leviathans that seek to come ashore. (They later learn that the Apoths of the Shroud have discovered a way to transport leviathan marrow—needed for these augmentations—which means the Shroud is no longer necessary and the Empire no longer desires to annex Yarrow.) Discrepancies in Sujedo’s physical description lead Ana to conclude that the true Sujedo never made it to Yarrowdale; instead, he was replaced by an imposter who escaped through the window using magnets to control the locks. Din discovers that the imposter accessed a lockbox belonging to Immunis Rava Ghrelin. Inside, they find a mummified head and a mysterious message.

Ana and Din meet with Ghrelin and Commander-Prificto Kulaq Thelenai who, despite their eagerness to catch the imposter, keep secrets. Ana and Din search through many Apoth records, looking for clues about the imposter’s identity. Ana reveals she knows that Din wants to transfer to the Legion and offers to recommend him for transfer when he becomes eligible, though she contends he will want to stay with the Iudex. Din meets with Prificto Kardas, the head of the Treasury delegation in Yarrow, where he encounters two important courtiers in the Yarrow court: Thale Pavitar, who is against Imperial presence in Yarrow, and Satrap Danudo Dari, who is in favor.

Malo and Din follow reports that Sujedo was seen near a smuggler’s camp outside the city. They find that the camp has been horrifically destroyed as titan’s blood has been aerosolized and sprayed, causing the smugglers to transform into grotesque creatures of plant and bone. One living, captured smuggler reports this was the work of “the pale king” (185). A shrine to the king suggests a connection to the Yarrow court.

Clues from the shrine compel Thelenai to admit that she has been illegally augmenting Apoths, making them into “augurs,” who have extremely strong skills at detecting patterns. Augurs have been instrumental in the project to transport titans’ marrow while it is alive, which would render the Shroud unnecessary, but spending too long as augurs drives the affected to madness. Ana contends that the imposter is presumed-dead augur Immunis Sunus Pyktis. She worries that Pyktis, who has used only part of the weaponized titan’s blood at his disposal, has greater and more dangerous plans concerning the marrow. She writes to Kardas, warning him of a potential villain in the Yarrow court, but is too late; late that night, the Yarrow king is killed.

At the summons of Prince Carmak (who is secretly Pyktis, his identical twin, in disguise), Ana, Din, and Malo go to the king’s hall. The elderly Yarrow king is revealed dead by poison; the poison comes from the same nuts that Din found at the pale king’s shrine. After questioning the different members of the meeting in which the king was poisoned, Ana realizes that Signum Gorthaus, Kardas’s assistant, was being blackmailed into providing Pyktis with the information he needed to steal the titan’s blood. She dies of poisoning before she can reveal her allies at court. (Ana later learns that Darhi was her correspondent.)

Kardas, who was also poisoned but not fatally, admits that the Empire no longer intends to annex Yarrow. Malo is horrified, as this means that the enslaved people of Yarrow will not get the freedom they were promised. The plan to withdraw from Yarrow will not work, however, if the marrow cannot be safely transported off the Shroud. To seek more information about Pyktis, Din goes to the Shroud to speak with other augurs. The augurs reveal that Pyktis had small totems and a silver object, symbols of the prince of Yarrow.

Din returns to Yarrowdale to learn that Darhi has fled the Yarrow court with large amounts of treasure in tow. Ana contends that Pyktis was the son of the Yarrow king who was raised in the Empire so that he could come to Yarrow as an Imperial citizen and destroy the Shroud. When his first attempt to do so failed, he sought aid from the king, whose extreme age and failing memory led him to not recognize Pyktis. Din and Malo pursue Darhi, who is killed during the attempt to capture him. They find what appears to be Pyktis’s body with Darhi, as well as most of the dangerous titan’s blood. Some is missing, however, suggesting that Pyktis’s trap is already set.

Ana, desperate for answers, takes a strange hallucinogenic substance, which causes her to undergo an eerie transformation. (Din later learns that this is due to her role as a Khanum, a descendant of a powerful but mysterious—and extinct—race within the Empire.) She sends Thelenai to the docks to seek Pyktis’s weapon, which Thelenai disarms. Ana, Din, and Malo head to the king’s hall, where they confront Pyktis, posing as Prince Carmak, by playing a discordant tune that is intolerable to an augur. Blotley welts all over Pyktis’s body confirm his identity. Pavitar, who is loyal to the crown, kills Pyktis for killing both the Yarrow king and prince.

Ana explains that Pyktis planned to destroy the marrow to force the Empire to remain in Yarrow. He would then take advantage of the Empire’s scheme to not annex Yarrow, extorting sums from the Empire and retaining his rulership as king. In the absence of its leaders, the Yarrow court quickly collapses, and the enslaved naukari flee to freedom, with Malo’s assistance. Ana leaves clues for Din to discover her role as one of the Khanum.

As the novel ends, Din agrees that he sees the purpose of the Iudex in preventing autocrats from taking and abusing power. He and Ana plan to continue working together, as Din no longer wishes to transfer to the Legion, even after Ana pulls strings to get the predatory lender pursuing Din shut down.