Disguises are a common motif in the mystery genre because hidden identities and motivations are essential to the construction of the plot. From the beginning of Finlay Donovan Knocks ’Em Dead, Finn is engaged in this kind of subterfuge. She disguises her identity on the forum—as do the other users—by creating a burner email account and using it to sign up for the forum using an anonymous username. She uses Bree’s identity when she interacts with the security company watching over Steven’s office at the farm. She pretends to be an accountant working with Steven’s business when she talks to the storage unit attendant. She also impersonates Kat at the jail and has Vero impersonate Irina at the car dealership while she impersonates Irina’s assistant. 

These are all literal examples of Finn using disguise—but there is also a figurative use of disguise that permeates her life and offers a metafictional comment on the genre itself. Finn is a writer of romantic suspense novels, and her hero is a thinly disguised but more self-interested and adventurous portrait of herself. Finn’s hero is not someone mistaken for an assassin—she is a real assassin. She is, like Finn, involved with both an attorney and a police officer—but she does wild things with them like have sex inside a jail.