Mark
CreativeMountainGames.com
There might have been a couple found drown near the shipyard supply shop and no one thought too much about it, as far as being a murder, until a third one occurs. Finding another person drown but in a place where drowning would be impossible, like at the butcher shop, could tip people off that there is much more going on here. Describing them as if they were "floaters" with the bloating and distorted features should make it plenty gruesome enough without the usual trope of having everything bloody. I'd imagine that if the PCs are walking down the street when they hear about the murder at the butcher shop and they rush over expecting a huge bloody mess only to be greeted by a drowning victim that ought to stun them somewhat. The cemetary might present as an interesting killing field with it perhaps being half under water though only a few inches. Of course it will be muddy and there will be no way to anticipate where open graves might be, and undead should not have any trouble since they do not need to breathe. You could use the stables location for some other type of encounter, a red herring between the butcher shop and the cemetary. If they go back to the shipyard to investigate the scene of the original muder, after it has been reclassified as a possible murder due to what has happened at the butcher shop, there could be some clues to be had there as well as some other sort of battle, perhaps something protecting a magical watercraft that is being constructed for the BBEG. It might even be a good place to bring the whole thing back full circle.