He had constructed, deliberately and over time, an apparatus for controlling a vulnerable person: the isolation, the dependence, the documents held hostage, the threats calibrated to her deepest fear, the pre-written confession, the money offered as a door out that was really a door locked behind her.

It was engineered.

And the thing about an engineered system, I knew from eight years of taking them apart, is that engineering leaves marks.

A crime of passion is hard to prove.

A machine is not, because a machine has parts, and every part is evidence.

Chapter 7 — The Ambush