The Justice Department’s antitrust division faces a major courtroom test beginning next week as it seeks to block the merger of two top book publishers, Penguin Random House and Simon & Schuster, under a unique legal theory.

DOJ’s argument is not that the proposed merger would harm book consumers, but rather that the merger of two of the so-called “Big Five” dominant publishing companies would stifle competition for what the government has termed “anticipated top-selling books,” and the authors who write them.