Too Far Back (The Flash and Merlin Crossover)

After Jay is killed, Barry tries to cross over back to Earth2. However, he accidentally time travels all the way back to the age of Camelot, and meets Arthur and Merlin. Being stuck there, he helps Merlin and Arthur fight Morgana, and when all is going well, guess who appears and joins Morgana? Zoom. Starts in The Flash Season 2 Episode 15 and right before Merlin Season 3 Episode 1. This also is a bit of a Glee crossover as well because it uses the idea of Barry moving in with his uncle Smythe in Ohio and changing his name to Sebastian Smythe because of bullying. (Posted on FF.net and AO3 as well).