Over the many seasons of Star Trek we have seen many crews of the USS Enterprise. But after the initial pilot was shot, the entire crew was actually fired except for Leonard Nimoy's Spock. Many Star Trek fans may have heard of The Cage, the first pilot of the show. But few probably know what led to everyone but Spock being replaced with a new crew including the famous William Shatner as Captain Kirk taking over the Enterprise. Star Trek would not be the franchise it is today without this major overhaul.