This wall seems to be the eastern wall of room 3 during a second, later phase of occupation, apparently also related to opus incertum wall 5343. The wall sits directly upon the tufo floor preparation/surface, and may also have remained in phase with it, more or less retaining the structure of room 3 from the first, ashlar-only phase. It is unclear what motivated or necessitated the construction of this wall, which seems to have replaced ashlar wall 5337 as the eastern limit of room 3. Based on the fact that to the north this wall seems to have extended into the space formerly occupied by ashlar wall 5341 (northern wall of room 3, robbed by 5427), it would post-date the robbery activity, and may be related to a larger reorganization of the area.