 The screenplay was conceived by Jerome Bixby in the early 1960s and completed on his deathbed in April 1998.The screenplay mirrors similar concepts of longevity which Bixby had introduced in "Requiem for Methuselah", a "Star Trek" episode he wrote which originally aired in 1969.The film gained recognition in part for being widely distributed through Internet peer-to-peer networks, which raised its profile.