Just the chat

During the active period MTF 420A-420D have reported hearing voices coming from the passenger compartment. The voices are described as numerous and often difficult to distinguish from one another. Where MTF 420A-420D have reported understanding the voices the content of their speech often appears to have significance only to MTF 420A-420D, while appearing entirely meaningless to others. No persons other than MTF 420A-420D have been observed entering or leaving the bus at any time. MTF 420A-420D have been observed referring to these phenomena as "the chat".