From Mann's Thief: Top left: Barry, on left, explains to Frank the operation of one of the alarms in the bank vault the two men plan to rob. When the alarm is triggered by someone entering the vault area, a code word must be transmitted over the alarm company's radio within ten seconds, to override the alarm and keep the police from being notified. Top right: The bank manager, here shown inside the vault area as the bank is first opening in the morning, speaks the code word over the radio to override the alarm: "Mexico." Above left: Barry, who has bugged the radio, intercepts the code word while hiding in the stairwell just outside the vault area. Above right: Later, when the robbery has begun and the alarm has been triggered, Frank speaks the code word: "Mexico." The word being spoken is a hint from Mann, about what we said earlier in this analysis: Kubrick set the 'Dawn of Man' in Mexico, not Africa.
The film Thief involves a diamond heist; as we will see later in this analysis, so does A Space Odyssey.