" As they proceeded, Leo explained how humans kept the last of the remaining apes (who couldn""t talk) in zoos where he lived, and although he admitted that humans were intelligent, he observed: "The smarter we get, the more dangerous our world becomes.Ryan observantly survived his attack and then attempted to alert Catherine by car phone of the threat, but he couldn""t prevent their car from crashing into a highway barrier.If you wanna get outta here, you talk to me.(later that night) Okay, so that""s my offer.I deliver a rig big enough to haul that tanker of yours, you give me back my vehicle and as much juice as I can carry.The screenplay for the film, written by Jerry Wald, Richard Macaulay, and Robert Rossen, was based on an original screen story by Mark Hellinger.