Book I of Plato's Republic is unusually eventful, yet one episode stands out: Socrates' exchange with Thrasymachus. Thrasymachus' challenge raises a hurdle that Socrates must overcome if he is to convince the audience -- both those present and those reading his account of the discussion -- that, despite plenty of evidence to the contrary, might does not make right. That challenge, however, puts Socrates in the awkward position of having to prove Thrasymachus wrong without appearing to overpower him in the argument and thereby inadvertently proving his opponent's point. Socrates thus allows Thrasymachus to take the reins of the inquiry, only to overthrow and replace him. Once in charge, however, Socrates admits that his own rule over the inquiry ended in an injustice. Socrates' surprising admission signals that his demonstration was necessary to clear the ground for the discovery of justice. His power struggle with Thrasymachus thus renders Book I an indispensable part of the Republic, and foreshadows the interlocutors' troubling realization that justice and power are ultimately impossible to reconcile fully.