A female actor re-enacts the work undertaken by women of the Auxiliary Territorial Service (ATS) during WWII, who were responsible for intercepting German transmissions at a British Listening Station's (staged here in the Museum's Tunny Gallery). At the Listening Station, the received signal was traced using a pen undulator - a machine which visually depicted the signal as a thin line on a piece of paper tape. In charge of turning this linear trace into something machine readable were the women of the ATS, who transcribed the intercepted transmission to binary five hole punched tape. Typically, messages could be between 1000 and 60,000 characters in length, although one message was reported to have been approximately 100,000 characters, which would have taken over 27 hours to type out! The punched tape was then passed on to a cryptologist, who would attempt to break the code.