Will Anderson and Elizabeth Hume are called to the vast Eloise Insane Asylum outside of Detroit, where Elizabeth's cousin Robbie is a patient and now a murder suspect. The victim, like three others before him at the asylum in recent months, was killed with the infamous "Punjab lasso," the murder weapon of the Phantom of the Opera.

Certain of Robbie's innocence, they begin an investigation with the help of Detective Riordan. Will has himself committed to the asylum to investigate from the inside, and Elizabeth volunteers at Eloise and questions people outside the asylum. While Will endures horrific conditions in his search for the killer, Elizabeth and Riordan follow the trail of a murder suspect all the way to Kalamazoo, where they realize the killer might still be at Eloise, putting Will in extreme danger. They race back to Detroit, but will they arrive in time to save Will and bring the killer to justice?

Filled with Johnson's trademark roller-coaster plot, nuanced characters, and brilliant historical research, Detroit Breakdown is a compelling, dark mystery set in the once- flourishing Paris of the West.