Live-in nurse hired to care for dementia-stricken Iris Blum. She investigates supernatural occurrences and discovers rough drafts of Iris's novel, leading her to believe it depicts a real historical murder. After confronting the ghost of Polly, she dies of a heart attack and later haunts the house as a protective spirit.
Lily transitions from a living protagonist to a posthumous haunting presence.
Mr. Waxcap acts as the employer who recruits Lily for the estate.
Lily is employed as the primary caregiver for Iris, establishing a formal professional bond.