Everyone knows someone with mental illness; few people have a friend who can know them from as many perspectives as Rosen knows Michael Laudor. They grew up together, attended college together, then set out on parallel paths. Laudor’s detoured into illness before ending in violence. The Atlantic excerpt left me in tears at the murder of Caroline Costello. The full book builds more gradually, but deepens the tragedy. This could have been a true crime story, but in Rosen’s telling, the crime was perpetuated by policy-makers, intellectuals, and physicians who mislead the care of persons with mental illness. The story remains a tragedy, but the in the book-length version the tragedy broadens.