Harriet is a 31-year-old successful mystery novelist and a graduate of Shrewsbury College at Oxford University. Three years prior, she stood trial for the murder of her lover, creating a public scandal that still colors her reputation. She prefers the logical world of academia over emotional entanglements and strictly guards her independence. When disruptive incidents threaten her beloved college, she returns to investigate the matter privately.

Wimsey is a 45-year-old aristocrat who works for the Foreign Office and acts as an amateur detective. He holds a master's degree in history from Oxford University, where he graduated at the top of his class. He values intellect highly and views Harriet as his absolute equal, patiently maintaining his courtship despite her repeated refusals.

A formidable middle-aged historian and recent addition to the Shrewsbury faculty. She maintains an absolute dedication to factual truth and academic integrity. Her strict adherence to principle leads her to expose academic dishonesty regardless of the financial or social cost to the offender.

Annie is a scout, or maid, who serves the housekeeping needs of the faculty at Shrewsbury College. As a working-class widow, she boards her children with local families because college servants must live on campus. Her husband's failed career left her destitute, forcing her to take domestic work to support her daughters.

The Dean of Shrewsbury College. She is a practical administrator who recognizes the danger threatening the college's reputation. Rather than calling the police, she quietly writes to Harriet to request her investigative expertise to solve the campus disturbances internally.

The Warden of Shrewsbury College. She bears the ultimate responsibility for the institution's welfare and its standing at Oxford. She actively resists involving outside authorities to prevent public gossip from damaging the cause of women's education.

A history tutor at Shrewsbury College. She resents married women who expect preferential treatment, believing that academic dedication should not take a back seat to family life. She frequently voices suspicions regarding the motives of men visiting the campus.

The Sub-Warden of Shrewsbury College and Harriet's former tutor. She is a kindhearted but thoroughly disorganized scholar whose massive manuscript on English prosody becomes a target for campus vandalism.

Lord Peter Wimsey's handsome and wildly irresponsible nephew. He attends Oxford as an undergraduate and frequently finds himself in physical or financial peril. He relies entirely on his uncle's wealth to resolve the debts generated by his careless behavior.

A 20-year-old student at Queen's College who engages in reckless campus hijinks. He develops an intense infatuation with Harriet after she helps conceal his trespassing from the college authorities.

An unmotivated university student who indulges heavily in social events and alcohol. She attends Oxford solely to satisfy her parents' demands, which angers serious scholars who view her as wasting a valuable placement.

A shy, intellectually gifted third-year student at Shrewsbury College. She works exhaustively to prepare for her final exams, pushing herself to the point of severe nervous strain and emotional vulnerability.

A former academic whose career ended in disgrace years prior. He stole a historical document to support a false thesis, and the subsequent exposure ruined his livelihood and drove his family into severe poverty.

A porter at the college who supplements his income through petty theft and blackmail. He provides child care for the college's live-in servants until his criminal behavior forces his dismissal.

A practical member of the Shrewsbury faculty. She strongly advocates for bringing the police in to handle the college's escalating security crisis rather than relying on private investigations.

A married secretary working at Shrewsbury College. She receives preferential housing accommodations because she has a child, generating significant friction among the unmarried academic staff.

An author and faculty member at Shrewsbury College. Her published work makes her an early target for the vandal attacking the college's intellectual resources.

A second-year student at Shrewsbury College who becomes the target of threatening letters demanding she break off her current engagement.

A male student from another college whose romantic entanglements cause friction among the female students at Shrewsbury.

A faculty member at Shrewsbury College. Her stolen academic robe is used to dress a disturbing effigy left in the college chapel.

Lord Peter Wimsey's highly capable manservant. He assists his employer with the technical aspects of criminal investigation.

A reliable porter at Shrewsbury College who assists with campus security and monitors the gates.

A servant at Shrewsbury College who helps alert the administration when vandalism is actively occurring in the science rooms.