Almost 25 years after Caleb Carr first thought a novel he was writing would make a good movie, a screen version has finally been made. "The Alienist," a 10-episode series based on Carr's 1994 novel of the same name, premieres at 9 p.m. Monday on TNT. It is about a psychologist hunting a serial killer in 1890s New York City. "I don't know how the series is going to do," says Carr, chatting on the phone last week from his home in Cherry Plain, a hamlet in the town of Berlin.