In the third installment of Men In Black, Agent J wakes up with a craving for chocolate milk, which leads to the discovery that time has been manipulated.
Agent J then goes to Jeffrey Price to gain access to a time travel device. When Agent J confronts Price, Price remembers sending Boris back in time, and is even missing one of the time devices in his case (which originally held two).
If the time line has been altered and Boris was never imprisioned in Lunar Max prison, why does Jeffrey remember helping to send him back?
