Gene L. Coon wrote the "Arena" script over the course of a weekend. When he brought it for approval on Monday morning, Joan Pearce, a Desilu research assistant, reviewed the script and discovered that it bore similarities to Brown's 1945 short story, also called "Arena." Coon and Desilu executives decided to buy Brown's story to be able to film the script, resulting in Brown receiving story credit. (Inside Star Trek: The Real Story pp. 206-207)