Part of the "mermaids curse" was disturbing the mental stability of those aboard the Obra Dinn.
This Troper loves Return of the Obra Dinn and finds it overall very tightly plotted and well put together. But one character's actions left this tropper scratching his head. Fillip Dahl's actions felt inconsistent. Why did he attack John? What was he looking to accomplish? If he really was trying to warn the others about the mermaid's curse, how was attacking John meant to send this message? And why was he so certain of the mermaid's curse in the first place, what exactly gave him these convictions? It cannot just be explained with him being superstitious: in Scandinavian folklore, mermaids are seen as benevolent. Later in the lazarette, why was a man who was suspicious of the mermaids not suspicious about the contents of the chest? Why did he impulsively touch the contents and get himself killed? Attacking John and touching the contents were both very impulsive actions, but this is inconsistent with the captain's dialogue saying he never doubted Fillip's sanity after twenty years his steward. Why was a man who showed no signs of instability for twenty years suddenly so impulsive?
So I came up with what is the only explanation that I can think of to answer these questions. The "mermaid's curse", in addition to bringing the crab riders and the kraken, also somehow effected the mental stability of those aboard the Obra Dinn. For unexplained reasons the effects of this curse are inconsistent. Fillip's Sanity Slippage is quick and severe, while other characters manage to keep their heads on straight for the rest of their time alive. Perhaps the curse only worked on people with some level of existing mental instability to exploit. Or perhaps the mermaids were able to direct the sanity slippage towards specific targets in order to maximize damage. Or perhaps the effects of the curse were simply random and unpredictable.
- The "mermaids" being able to drive people mad makes sense, if you assume they're actually sirens, who are known for driving sailors to their doom just by listening to their voices.
While it was Fillip's actions that inspired the creation of this WMG, and only his actions don't make sense to this troper without the explanation of the curse, his actions are far from the only example of actions that can be explained by a curse of sanity slippage. Other examples include:
- Thomas Sefton's dumbass behavior around the mermaid which got him killed, which would make him the only other character to be noticeably effected by the curse immediately
- Marcus Gibbs impulsively attacking the crab rider with a thrown axe, despite calls to stop him
- Abigail impulsively searching for her husband in the middle of a kraken attack
- Nathan Peters killing Lars Linde in misguided revenge for his brother
- Leonid Volkov attacking the escapees and not listening to the captain tell him to stop
- Olus Wiater's mutiny attempt and subsequent decision to kill Thomas
- Brennan clubbing John Davies without waiting for an explanation
- William Hoscutt, Harry Brennan, and Lewis Walker turning on the captain
Of course any of these actions could also simply be the individual character's own impulsivity, stupidity, paranoia, greed, or so on. Only Fillip's behavior lacks a good explanation without the explanation of the curse, but it would not make sense for only Fillip to be effected by a sanity slippage curse. This troper can think of no better explanation behind Fillip's behavior, and therefore is presenting this WMG to fill that gap.
Note that this sanity curse theory has a side effect of making the mermaids more malicious, therefore committing to one side of the Alternate Character Interpretation debate about the mermaids. The effects of the sanity aspect of the curse continue after the conclusion of "The Bargain", meaning the mermaids did not lift the entire curse. They may have been exploiting a loophole since no one ever asked them to "lift the curse", Captain Robert only asked them to call off the kraken and Martin only asked them to see the Obra Dinn home, which in both cases they technically did. Another explanation, which acquits the mermaids of bad intentions after The Bargain, is that the mermaids were in fact incapable of lifting the sanity aspects of the curse once they had been set in motion. It is also possible that the mermaids were unable (or unwilling) to reverse the damage done by the curse, meaning that the minds of those effected remained damaged and that actions committed after The Bargain were due to existing damage done by the curse.
The powers of the Memento Mortem only manifested late into the voyage.
By the time of The Bargain, Henry Evans is clearly aware of the power of the Memento Mortem, otherwise his action of shooting the monkey inside the lazarette makes no sense. However, as brought up by another troper in Headscratchers, why did he not use it to see who the true culprit behind the murder of Nunzio Pasqua was? If it was discovered at that point that Nichols was behind it, the whole tragedy could have been avoided. The only explanation I see to this is that when Pasqua was murdered, the Memento Mortem was nothing but an ordinary pocketwatch in Evans' possession. The mermaids' shells are clearly interacting with the watch, as they're the only thing that's animated in the death scenes, so it's not unreasonable to think there might be some connection. If the shells somehow granted the Memento Mortem its power, by the time Evans would have found this out Pasqua's body would have been long gone, and the only corpse that could have gotten him back to it (namely Timothy Butement's) was hanging outside the First Mate's window seemingly undiscovered until Evans was already in the process of leaving the ship.
- Especially noteworthy about the shells' animation in The Bargain is, that unlike in the scene shown by the Memento Mortem, the book shows Fillip Dahl's corpse without any of the rays emanating from the shell, because the latter is how it appeared to an onlooker - like Captain Witterel, who completely overlooked what appears to be a brightly radiating shell. So, why is the shell brightly glowing in present day? Presumably, because the mermaid activated its power as a signal to whoever investigated the ship, that the Obra Dinn did not just randomly return home, but she kept her end of the bargain.
- The Memento Mortem having gained its powers from the shells makes sense for one more reason - the game never explains how the mermaid knew where to return the Obra Dinn to - in fact, Falmouth was not the starting point of its journey. It was however the location the first deaths occurred during the journey - one of the corpses from these events was actually still aboard. Assuming the shells have similar or, likely, stronger powers than the pocket watch, the mermaid could have used them to figure out an early point of the ship's journey and returned it there.
The two crab-riders' bodies are probably the two mutineers who were pulled overboard during Nichols' mutiny.
Not much to support this thought. Nichols' did toss over the other dead bodies after the fighting (minus the Formosans' bodies), but the two mutineers who were dragged overboard during the chaos were very much alive at that time. Following that, two giant crabs with one "rider" each attacked the Obra Dinn, each appearing as a corpse covered in seaweed. That said, there's no trace of the bodies after the crabs are slain, and no one makes mention of the "riders" specifically.