One of the novel's many examples of foils can be found in Ken Erdedy and Michael Pemulis. Chapter 2 centers on Erdedy's anxiety while he waits for a fix:
[H]e moved first toward the telephone console, then over toward his intercom module, then convulsively back toward the sounding phone, and then tried somehow to move toward both at once, finally, so that he stood splay-legged, arms wildly out as if something’s been flung, splayed, entombed between the two sounds, without a thought in his head.
Erdedy has been waiting for hours for his dealer to arrive, and he is desperate not to be pulled into an interaction with anyone else. Now that both his phone and his front door intercom are ringing, he is pinned in place by the thought that he might choose the wrong one. Throughout this chapter, Erdedy has been watching a bug on the wall. In this passage, he begins to look just like the bug, stranded in his apartment and flailing in thoughtless panic.
Erdedy is the first character the novel introduces through the lens of his addiction, and it is a bleak picture. When Erdedy appears again later in the novel, he is one of the sober residents of Ennet House. The reader may be surprised to learn that before addiction took over his life, Erdedy was a successful Harvard graduate with a desk job. Erdedy is evidence that class privilege is not a real shield against addiction. Once it sets in, even the most well-off people can be brought low, to the point that they lose control of not only their careers but also their logic and bodily functions.
Michael Pemulis at first seems like he might be a future Erdedy. He attends an elite prep school, and his relationship with drugs seems more troubled than he realizes. The relationship between these characters turns out to be a bit more complicated. The novel hints that a scholarship to E.T.A. offers a way for Pemulis to climb up the social ladder from a lower rung than Erdedy, but it is not until the narrator gets inside his brother's head that the reader gets a clear picture of just how high the stakes are. For Pemulis, both E.T.A. and intoxication provide escape from an extremely traumatic childhood. Erdedy takes his creature comforts for granted and loses many of them through his addiction. These same comforts are far more precious to Pemulis, representing safety from the family trauma he would have to endure if he were ever forced to move back home. They move in opposite directions prior to the start of the novel: Pemulis's upward mobility matches Erdedy's downward mobility. By the end of the novel, though, Pemulis is being expelled. It seems, heartbreakingly, as though he may lose even more than Erdedy ever did.