sentences:  Rick Baker appears in a cameo as the Brain Alien.Tony Shalhoub has an uncredited cameo as a 1960s Newsdealer.The film's premise was first proposed to director Barry Sonnenfeld by Will Smith during the filming of "Men in Black II" in 2002, with Smith suggesting that his character, Agent J, travel back in time to save his partner, Agent K, while at the same time exploring Agent K's backstory.