By Kevin Wignall

Simon & Schuster. 209 pp. $22

One basic fact about the book business is that many, many more books are published than can be reviewed. In my little corner of the book universe, this means that the editors send me huge boxes of new novels and I have space to review maybe one in five of them. I try to find the best books I can, both because I don't want to spend my time reading mediocre novels and because I want to alert readers to good books they might not find on their own. In particular, I look for the occasional gems by new or little-known writers that arrive amid all the junk. To that end, I read a chapter or two of everything that comes in. In my experience, if a novel starts off badly, it isn't likely to turn into "The Great Gatsby" on Page 35, and if one starts off really well, there's a good chance it will stay that way. But there are exceptions. Take for example Kevin Wignall's second novel, "For the Dogs."

In its first chapter, a hit man enters a home in a London suburb and kills a businessman named Hatto and his wife and 17-year-old son. His work done, the hit man calmly leaves the house, and we are told that the dead boy's sister, "wherever she was," is also in danger. In the second chapter, we find Ella Hatto, who is 20 and a college student, in an Italian village with her boyfriend, Chris. As they relax in a sidewalk cafe, Ella notices a man nearby she thinks she has seen before in Rome and Florence. He is fortyish, ordinary-looking. The man abruptly gets up and shoots dead two men who are approaching. He tells the two students to come with him, calling Ella by name. Stunned, intimidated, they go with him to his car, and they drive away. He says his name is Lucas and that Ella's father hired him to protect them. The men he killed were probably kidnappers, he says. None of them knows yet that Ella's family has been slaughtered.

All this is nicely told. The writing is smooth, taut, understated, unsentimental. The situation is interesting. Who is seeking to wipe out Ella's family? Who is Lucas? I was sufficiently intrigued to put the book aside for review. Alas, after that promising start, "For the Dogs" began to fall apart. The writing continued to please, but the story became increasingly improbable. The three take refuge in a hotel in Florence. Chris is increasingly a jerk. Another assassin turns up and is killed by Lucas just seconds before he would have shot Ella. Lucas needs only to deliver the two students to a police station or British consulate, but instead he endangers himself by taking them to his home in Switzerland. They learn that Ella's family is dead. Lucas reveals that he is a professional killer, retired after more than a hundred hits. He proves to be a sensitive, bookish hit man. He is reading "A Journal of the Plague Year" and the German epic poem "The Nibelungenlied." Ella, an English major, turns him on to Jane Austen. There is a bit of flirtation between them.

Ella goes home. The obvious suspect in the murders is her father's brother and business partner, Simon, but she refuses to think her uncle could be responsible. Ella goes back to college, where everyone has heard rumors that her father had mob connections. Chris rejects her ("You need to see a shrink"), and another student makes jokes about her putting a horse's head in his bed. The police get nowhere with their investigation. Ella is increasingly filled with fury ("There was definitely a sickness within her"). Determined to avenge her family, she calls Lucas, who obligingly comes to help her. He refuses her money, and there is no hint of sex between them; his motivation for putting his life at risk to help this increasingly deranged girl is that "he wanted to be there for her, that she was a good person and deserved better than this." What we have here is a hit man with a heart of gold.

Lucas finds and kidnaps the assassin who killed Ella's family and presents him to her. The killer reveals the name of the middleman who hired him. That is enough for Lucas, but Ella insists that he kill the assassin. Ever obliging, he does; then Ella demands his gun and fires another shot into the corpse. Her blood lust aroused, she next eliminates the middleman who arranged the hit and manages to kill three innocent people in the process. We are asked to believe that this rather ordinary girl has been transformed into a killing machine who makes Aileen Wuornos look like the Flying Nun. Meanwhile, the professional killer, Lucas, is establishing contact with a 14-year-old daughter he has never known because her mother walked out on him when she learned his true calling.

There is a certain symmetry here -- hit man goes domestic, English major goes ballistic -- but I never believed a word of it. The novel ends with a showdown that is as bloody as it is ludicrous. Wignall was born in Belgium and now lives in England. His first novel, "People Die," earned some good reviews, so I can only assume that this one reflects that old bugaboo, the second-novel slump.