Sleepy Hollow had already been meandering and pointless for a lot of the second season, but then there was an episode where they just full on ended the ongoing storyline. The next episode was basically the characters going "what do we do now?" the rest of the season was MOTW episodes not connected to anything, and after all that, which was pretty clearly the network stepping in after all the meandering, they fired the showrunner, season 3 was like a bad USA show, and in 4 one of the leads left and it wasn't even set in Sleepy Hollow anymore. Oh, and there was a Bones crossover. So yeah, that's my answer - wrapping up the main conflict 11ish episodes into season 2.