Denise Mina's fourth novel Deception takes the form of the published diaries of Lachlan Harriot, whose wife Susie has been convicted of murder. As a court- appointed psychologist, Doctor Susie treated notorious serial killer Andrew Gow and the young wife he met in prison. Susie allegedly had an affair with Gow and then killed him. As Lachlan Harriot's diary begins, Susie is on her way to prison, but Lachlan cannot believe his wife, a respectable person and the mother of his child, could have committed such a gruesome crime.

As Susie begins serving her life sentence Lachlan sorts through material left in her home office, determined to find evidence that will prove her innocence. Before Susie's arrest she was physically and emotionally distant from Lachlan and often simply ignored him, using her office as a retreat from him and their small daughter. Lachlan now rifles the office and invades Susie's privacy; his diary includes transcripts, descriptions of photographs, and newspaper clippings as he combs through boxes and files, listening to taped interviews, examining her books and struggling at once to uncover and to deny the truth. Lachlan pines for Susie and makes excuses for her, searching relentlessly for evidence that will explain her behavior or disprove the case against her, finding instead more and more evidence of her duplicity and guilt.

It is apparent Lachlan was not only deceived but has somewhat comically deceived himself about Susie's fidelity and marital happiness. However, as Lachlan learns more about Susie and her relationship with the Gows, the plotting becomes more complex, offering further, surprising subterfuges and a final unexpected twist to Doctor Susie's story.

Deception is a very satisfying psychological portrait of Lachlan Harriot as a man at once pathetic and scheming, a victim who might be no more trustworthy than his murderous wife.