If you've ever played with magnets, you know that opposite poles attract and like poles repel each other. This is the basic principle behind electromagnetic propulsion. Electromagnets are similar to other magnets in that they attract metal objects, but the magnetic pull is temporary. As you can read about in How Electromagnets Work , you can easily create a small electromagnet yourself by connecting the ends of a copper wire to the positive and negative ends of an AA, C or D-cell battery . This creates a small magnetic field. If you disconnect either end of the wire from the battery, the magnetic field is taken away.
As the novel progresses, Bruce's mental health begins to deteriorate; it is revealed that he suffers from drug addiction and bipolar disorder , which, along with his inability to form meaningful, trust-based relationships, are exacerbated by latent, unresolved psychological problems caused by childhood abuses. Eventually Bruce is forced into taking leave due to injuries he suffers while dressed as his ex-wife, leading to the revelation that he committed the racially motivated murder that serves as the novel's main plot and that the colleagues he despises – particularly his boss Robert Toal – have been aware of his guilt all along and have been protecting him from the consequences of his actions out of a mixture of loyalty and pity . At the end of the story, Bruce kills himself, with his last thoughts being regret and hoping that his daughter does not know of his suicide.