Is a writing agent a writing agent, or do they specialize in a certain field? If I'm working on a teleplay, or a screenplay, would the same agent handle that as a novel? Or does it all depend. Right now I have an idea for a spinoff series of a current series that I'm super stoked about. I have great ideas on how to wrap up the universe that has already been created, but I don't know how to begin. Do I have to start with a treatment, and would an agent even look at something I do for an already existant show if I haven't created something unique and of my own? I don't particularly know how to get my foot in the door on this one. Unless I go to a comicon and bug the hell out of the creators.
All i know is that agents specialize in certain genres and types of works and usually say what they are interested in on their websites or somewhere like Writers Market. It's probably because they have experience in that market and know who'll buy that type of work.
It's a good idea to research an agent before querying. Through this research you should be able to find exactly what genre(s) the agent represents. The internet + Writer's Market can help with this, as mentioned. Wouldn't the end of a series be written by the same people who begun the series? I'm very confused.
...not necessarily... agents all have their areas of expertise and experience and list their medium and genre preferences on their sites and in agent listings... ...if you want to be a screenwriter for film or tv, it would be best for you to have a 'hollywood agent' [i.e., one who reps screenwriters exclusively] instead of a 'literary agent' [one who reps books]... ...no!... there is an industry mandated way to present a series concept proposal... it includes a 'bible' and full scripts of sample episodes, plus thumbnails for a half-season of episodes and other components... however, you can't legally write that unless you have the permission of the current series' producer... do so and you can be sued for plagiarism and whatever else they can throw at you... ...no!... nor would anyone connected with the current series, as their legal departments don't allow it... if you were to send your proposal to the producer, it would be returned unopened, with a warning from the network's/production company's legal eagles... ...the only way is to get a low level job in the industry and work your way up, making helpful connections as you go, or become a professional screenwriter with a good track record and an agent with good tv industry connections... ...that can get you in hot water, too... ...this applies to the us tv industry only... it may be easier to break into the uk or commonwealth tv world...
I think you call them literary agents. Do you mean a story about a universe that you created, or that someone else created? If you mean someone else created, you are out of luck. That is fan fiction. You can't sell that stuff. I know that because I am a Twilight freak. Lady Sybill's wrote a novel she called Russett Moon, which uses some of SM's characters and she was warned that if she tried to publish, the weight of the big publisher would come to bare. She even had a publisher lined up, but I think a teeny tiny one. But if it's a universe you invented, and not one you just like to play in, then you're good to go.