Doctor Death is back. The serial killer Michael Bekker aka Doctor Death is back in this number 4 in John Sandford's Prey-series. After being arrested and beaten up by Lucas Davenport in a previous novel, Bekker escapes prison and sets himself up in New York. Bodies start turning up, and Davenport's ex-lover New York cop Lily Rothenburg calls to Davenport for help. He is not working with the Minneapolis Police anymore, but spends his time developing computer games. He welcomes the chance to work with Lily, and goes to New York. He soon finds out that Lily and her chief of Police O'Dell has a hidden agenda. Davenport is not called to New York only to solve the Bekker case: there is a "Robin Hood" on the loose in New York, killing "bad guys" and everything points to someone inside the police department. Davenport is asked to figure this mystery out, while he officially works solving the Bekker case. The story is great and the plot smart. Although you know who the killer is from page one, you keep guessing almost to the end, how does he do it, how does he manage to keep hiding? And who is the Robin Hood? Is it Lily herself, killing off bad guys from the streets of New York? There are many layers in this story, but it never becomes boring, and the characters are likeable or realistic. A good read in the Lucas Davenport series.