Enredo

When a serial killer reappears, the team works with a retired BAU agent who just published a book about the perpetrator.

Retired BAU profiler Max Ryan is on a book tour, his book on the Keystone Killer, an unsolved case on which he worked twenty years earlier. The Keystone Killer murdered seven women in Philadelphia over a two year period, he communicating with the media through clues to murder details hidden in word search puzzles. Eighteen years ago, the murders just stopped. Ryan believes the Keystone Killer is still loose and perhaps active. Ryan currently lives in Philadelphia, he who is still working on the case unofficially. While on a tour stop in Washington, D.C., one at which Gideon attends, the Keystone Killer is also there, he who leaves a message for Ryan including two drivers licenses, one of his last known victim, and the other of another woman named Carla Bromwell, who had since been found dead. Bromwell's death is atypical to the other seven in many ways, the BAU thinking that the Keystone Killer may be devolving as a killer. Ryan inserts himself into the case. The BAU welcome his knowledge on it, but find that he is less than a congenial colleague. But things become even more personal for Ryan as the Keystone Killer seems to be focusing his messages specifically to his old tracker.—Huggo

Just when Gideon asks his retired, notoriously intense ex-mentor Max Ryan, now a criminology author presenting his next book on the Keystone killer who got away after the last of seven killings of blond females -strangling Amy Jennings-, for a guest lecture, Max gets a note from the killer, quoting Steinbeck but spaced so that it's riddled with references to his former victims and both Amy's drivers license and that of an eighth victim, however now older and more violent, a script deviation which worries the team. Gideon observes Max, technically just a consultant now, is too personally engaged. A new note quoting Francis Bacon announces another victim two days later. The team follows a reference in the note to Scott Harbin, a recently paroled former suspect Ryan emphatically excludes, who fits the obsessive profile, and finds a live victim but conclude he's not the Keystone Killer. Ryan suggests the drastically changed MO must have an external reason, plausibly physical incapacitation- assuming a car accident in Philadelphia when the murders stopped leads to now rehabilitated criminology degree-holder Walter Kern, whose spine was broken in an accident near a victim's home and was professionally connected with Scott Harbin; his wife and home prove most interesting...—KGF Vissers