Chapter 40 Summary: Cyanide, DMSO, and the Altered Evidence
⚠️ Spoiler Warning: This guide contains detailed spoilers for the entire novel. Proceed only if you've finished reading or are comfortable knowing the plot.
Summary
Devine gapes when Dr. Coburn mentions garlic. She explains that cyanide is naturally occurring, used in industries, and kills by blocking cells from using oxygen, causing heart and nerve cells to shut down. Inhalation is the most lethal route; ingestion offers some time for treatment; absorption is slowest. She suspected cyanide because the Odoms' blood and skin were pink-red, indicating oxygen-rich blood, and she ordered ultra-performance liquid chromatography with mass spectrometry (UPLC/MS) to confirm. Coburn also detected a strong garlic odor, which led her to research dimethyl sulfoxide (DMSO), a substance that rapidly passes through skin and even rubber gloves. She theorized a dose of cyanide combined with DMSO was applied dermally, making absorption more efficient than typical skin poisoning. The victims' stomach contents showed no garlic, ruling out ingestion. Coburn kept her suspicions hidden from anyone in Ricketts.
When they access her cloud-based reports, they find the same false overdose narrative that had been planted on Devine's computer. Coburn realizes her original dictation recordings are likely gone. Devine concludes that everyone in Ricketts except Coburn may be complicit. The Odoms' bodies have already been cremated, eliminating further evidence. Coburn fears for her life. Devine says they need to get her to safety and contact the FBI. As he speaks, he hears a noise from the back of the house.
Key Events
- Coburn reveals cyanide poisoning as the cause of death for the Odoms and explains the mechanism.
- She describes the garlic smell that led her to DMSO and the theory of dermal application.
- Coburn's cloud reports have been replaced with a false fentanyl overdose finding.
- The original dictation recordings are likely destroyed.
- The Odoms' bodies have been cremated, preventing further autopsy.
- Devine deduces widespread corruption involving Doris Chandler and possibly others.
- The chapter ends with a menacing noise at the house.
Character Development
Travis Devine: Devine pieces together the conspiracy, moving from questioning to action. He remains calm and decisive, immediately prioritizing Coburn's safety. His protective instinct sharpens as he realizes the threat.
Dr. Coburn: She transforms from a confident medical examiner to a frightened whistleblower. Her expertise is confirmed, but her trust in the system is shattered. She shows defiance (“But I exist”) but also vulnerability as she grasps the danger.
Themes, Symbols, or Motifs
Corruption and Truth: The tampered cloud reports and cremation symbolize how evidence can be manipulated by those in power. Coburn's factual findings are overwritten, highlighting the battle between investigative integrity and institutional corruption.
The Duality of Medicine: Cyanide is both natural and lethal; DMSO, a medical vehicle, is perverted for murder. This reflects how healing tools can be weaponized.
Isolation and Danger: Coburn is isolated in Ricketts and now physically threatened. The noise at the end underscores that no location is safe.
Why This Chapter Matters
This chapter is a turning point. It confirms the Odoms were murdered using a sophisticated method, that local authorities are likely involved in a cover-up, and that the stakes have escalated from a single death to a widespread criminal conspiracy. Devine gains a key ally but loses the physical evidence. The cliffhanger ending propels the narrative toward a thriller climax.
Study Questions and Answers
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Why did Dr. Coburn suspect cyanide despite not smelling bitter almonds?
The bitter almond odor is not always present. She observed the victims' pink-red blood and skin, indicating oxygen-rich blood typical of cyanide poisoning. She also detected a garlic odor, which led her to DMSO. -
How was the cyanide administered, according to Coburn's theory?
She believes the cyanide was combined with DMSO and applied dermally. DMSO accelerates absorption, making the poisoning more rapid than typical skin absorption, but slower than inhalation or ingestion. -
What evidence supports that the authorities in Ricketts are corrupt?
Coburn's cloud reports were replaced with false findings of fentanyl overdose. Her dictation recordings are likely gone. The bodies were cremated before further tests could be done. Doris Chandler, who handles lab samples, may be complicit.