This paper reexamines the art and architecture of the Upper Temple of the Jaguars, Chichen Itza, in light of new unpublished digital images of Adela Breton's copies of the murals. Following discussion of the construction date of the building and previous interpretations of the murals, examination of costume, setting, and house form suggests that rather than depicting mythic or symbolic episodes, these murals illustrate actual military encounters between Chichen and its enemies. The occasion for their production seems to be the utilization of the Upper Temple of the Jaguars by a specific sector of Chichen Itza's military, perhaps for rites of investiture. This sector is argued to have been associated with the Cloud Serpent, either as the title of its leader or as a patron deity, and the structure itself is perhaps related to later Nahua buildings associated with penitential rites involving warfare and investiture.2 Line drawings of the murals were produced by Santiago Bolio (for Edward Thompson [McVicker 2005:72]), Augustus and Alice Le Plongeon, and Teobert Maler (cited by Seler 1998:109). With the exception of a tracing of the southwest panel and a portion of the northeast panel by Maler (in Willard 1926:217, 220), the others are unpublished. I have seen no indication that Thompson's copy survived.3 Martínez de la Luna (2005) summarizes the current state of the murals and some of the results of a recent Brigham Young multispectral investigation of the UTJ murals.