It was a truth universally acknowledged: Marcia Deaver's untimely death elicited very little grief from her colleagues at Valerian Hills High School. Some staff members speculate the cause of death was a heart attack, or perhaps a suicide, but Liz Hopewell knows no self-respecting English teacher would kill herself without leaving behind a perfectly penned suicide note, complete with detailed footnotes and obscure literary references.

After the police begin investigating the death as a murder, Liz finds Marcia's mysteriously coded lesson plans. Convinced they hold the key to the killer's identity, risk-averse Liz finds herself obsessed with the crime. Against the wishes of her husband and the handsome detective assigned to the case, she embarks upon a quest that takes her down a sordid trail of infidelity, blackmail, and Shakespeare conspiracy theories.

When additional staff members are also poisoned, Liz realizes her clandestine pursuit has spooked the killer, and she is likely next on the list. Can Liz expose the murderer before she becomes the next victim?