The Truth is in the Echo by taintedidealist
AO3
Complete: 5 Chapters, 10,688 Words
Rating: Mature
Triggers: Violence
Official Summary: A string of murders in Storybrooke point toward Regina, but Emma is struggling to believe that the Mayor has turned into the murderous Evil Queen again. Against the town’s wishes Emma works with Regina to clear her name and find the true killer. Spoilers: Set after 2x09 “Queen of Hearts and re-imagines large plot points of 2x10 “A Cricket Game”. No Hook. No Cora. That dried up bean just didn't get restored, darn.
Blog Opinion: Apparently this week is going to be creepy fic recs in the spirit of Halloween. Fantastically written, short as it is. The twist with the villain is a wonderful one, this is a quick read so I recommend doing so immediately.