The Steel Kiss (Lincoln Rhyme Novels, book 12) by Jeffery Deaver

Amelia Sachs is hot on the trail of a killer. She's chasing him through a department store in Brooklyn when an escalator malfunctions. The stairs give way, with one man horribly mangled by the gears. Sachs is forced to let her quarry escape as she jumps in to try to help save the victim.

Genre: Thriller, Fiction, Suspense, Mystery