The Alienist, written by Caleb Carr, is a gripping urban mystery fiction book set in 1896 New York City. The story follows Dr. Laszlo Kreizler, a criminal psychologist, as he investigates a series of gruesome murders. With the help of a journalist and a team of experts, Kreizler delves into the minds of the city's most dangerous criminals to catch the killer. With its vivid historical backdrop and intricate plot, The Alienist is a thrilling urban mystery that offers a fascinating glimpse into the early days of criminal profiling.