It's certainly a disturbing read, especially at first, where Maclean starts things off like an average tale about a man and his habits after work. Martin Gregory seems a regular Joe; he works in New York City, then takes a train back to his home in the suburbs where he lives with his wife Anna and their two dogs. Things seem fine between them, and Martin's even gone to the trouble of planning a spectacular birthday party for his wife. There will be presents, and food, and this first encounter is a charming meeting between reader and character.
That is, until Martin decides to murder their dogs by chopping them up and putting them in a white box as a gift for Anna. He locks her in their room, heads downstairs, and leaves before she wakes up, then immediately regrets his actions, claiming that he did them without knowing why. As he takes initiative and responsibility to go see a psychiatrist named Somerville, he is transported to a past that he doesn't remember, particularly because it seems he has had multiple past lives.
It's interesting to note how different The Watcher's beginning and ending are; what starts out as an eerie exploration of a man's motiveless killings becomes a psychological thriller where no event ever feels real. As Martin begins to visit his past in hypnosis with Dr. Somerville, he loses sight of his reality - and since he's mostly our only tether to the world of The Watcher, there are many avenues to explore in the novel, where the reader wonders what is actually happening or what is being exaggerated by the narrator.
That means that The Watcher can become a bit frustrating; it is developmentally meant to skirt the truth, surreal because of its subject matter, and from the moment that this plot element is introduced into the story it is clear that there can be no resolution where the reader clearly understands if Martin really has past lives or not. Inevitably, the ending pales because of this; Martin begins to see similarities in his past lives. In one, presumably his first, he steals a golden orb from his father and gives it to some people of the river, which causes an apocalypse. Martin believes that his quest from life to life is to recover the artifact, and he feels that Somerville is his enemy.
It's a complicated premise, and one that requires every chapter that Maclean gives us. And still the resolution is a bit iffy for my taste; it's easy to see coming (that there is no resolution either way) and it feels as though The Watcher gets stuck to its psychological plot too much.
Still, the surprisingly twisted opening and the multiple lives experienced by Martin make this a quick and fast-paced read. But enjoyment of the story depends on how willing the reader is to accept the fact that Martin might be crazy, or that he might be sane. And there's also the question of whether The Watcher of the title is real, or a red herring. Despite the evidence, there are multiple ways to interpret this novel, meaning that the reader can be elated or disappointed depending on how they read it.