There are nearly seven hundred live-action episodes of the Star Trek franchise. If you watched them all back to back, it'd take you more than twenty one days before you get to the end. Although if I were you, I'd skip the last episode of Enterprise. So with that many episodes of the series developed, it is unsurprising that a significant number of episodes went undeveloped. During various periods of the shows, the producers allowed unsolicited scripts to be sent in for consideration and a handful of those were made. At least one online reviewer was flown out to pitch story ideas for Star Trek: Voyager (incidentally - hey, new series producers, I'm over here!). But seriously, Star Trek has had some famous episodes and storylines go unproduced. Some end up being reworked and reworked until they become something different (Deep Space Nine's Time's Orphan episode originated as a Next Generation episode about Alexander), whilst others get completely canned (ever hear about the episode where Tom Paris gets his arm ripped off? Nope? Didn't think so). In some cases, they even become elements of other shows - I know at least one Farscape episode originated from a Star Trek concept. A number of science fiction writers worked for different shows at the same time they must have reworked failed Star Trek pitches and re-used them elsewhere. Plus of course you have Star Trek: Phase II - that had a full half season of stories planned out and only two were re-used for Star Trek: The Next Generation. So here are my 10 favourite undeveloped stories and ideas for episodes in the Star Trek franchise...