"Leave the World Behind" was a major letdown. Despite a promising start, the movie's plot quickly becomes convoluted and unrealistic, with far-fetched elements and hackneyed discussions. The tension becomes exhausting due to overuse of dramatic cinematography and an overbearing score. The horribly botched ending turns into a soap opera-esque lecture on societal divisions, leaving numerous unanswered questions and a sense of wasted potential. The commendable performances by the lead actors can't save this disjointed and preachy narrative. In short, "Leave the World Behind" is a frustrating watch that fails to deliver on its promising start.