I've been quietly suspicious of Zach for a few rounds now, and I think that he's been lying low for the majority of the game, and has only been active the last few rounds because he feels confident since the wolves are so close to winning. I'd say his confidence has definitely increased this round for instance, as he firmly accuses Emzies without any reasonable proof or justification whilst in previous rounds he seemed to have just jumped on the bandwagon when voting people off. I know he claimed to be a villager, but he just seems too confident to be just a villager in my opinion.
Therefore, I vote to lynch Zach.