This article provides a fresh evaluation of evidence on manuscript GA 304 (Paris, BnF, Grec 94). This manuscript is often quoted in critical editions of the New Testament as one of the three main Greek witnesses to the short ending of Mark. As part of the MARK16 project, the author provides a close examination of the manuscript’s content, with a focus on Mark 16. Afterwards, a closer look into the possible literary connection between GA 304 and the Gospels commentary of Theophylact will be made in order to understand the background of Mark’s short ending in this manuscript. Against recent assessments that downplayed its significance in the debates of Mark’s ending, this article argues that GA 304 stands as a good case for the author’s preference of the short ending, which must have been based on an authoritative source that shaped his decision. The manuscript’s complex relationship to Theophylact’s commentary shows how it should not be presumed that the former is posterior to the latter, and therefore it does not owe its ending to a redactional act of Theophylact’s catena. Therefore, this article opens the door for further literary examination of GA 304 against the wider pool of the tradition of Greek catenae.