Mermaid Story Ideas?

[WaveMaker04]

I'm working on a story that was inspired by this commercial: http://www.youtube.com/watch?v=uxwbpQz8oSs and it's kind of got elements of the original Little Mermaid, but here's the plot- A young mermaid named Zy and her best friend, a merman named Caspian learn that merfolk have no immortal souls. Therefore, they will never live among the stars as humans do after death. Determined to earn an afterlife, the two explore the ocean to find themselves a spirit.
I've got everything planned except THE most important thing; How exactly they could earn a soul. To be honest, the only good idea I could come up with is that sometimes the spirits of drowned humans lose their way in a forest of polyps (similar to the one described in the original Little Mermaid story)and if they help one find his way again, he'll give them a piece of his soul in return. But I'm not sure I want to involve ghosts or anything like that. I want the characters to be strictly merfolk or human. Does anyone have any ideas?

[Mermaid Momo]

mmm. maybe you could include an encounter with a god such as neptune,poseidon, or some other god you make up who they plead their case to. and gives them tasks to do in order to prove how much they really want a soul? ik now you said that you'd like to keep characters either mers or human so maybe the god can show up disguised as a mer?

[Mermaid Annariea]

that actually sounds like a really good idea. but i dont think you should only have two races...
i like the idea of the polyp forests, and i also really like the god/goddess idea. poseidon or calypso or something. (neptune and poseidon are one in the same. i just like the name poseidon better, haha.)
OR, maybe theyd have to do something theyre not okay with. like combine the two ideas... in order to gain a soul, they have to kill a human, but at the last second, they decide they cant do it, and theyre rewarded by poseidon or calypso for not going through with it, maybe because it happens a lot (sirens (enchanting and drowning sailors) = mermaids wanting to have souls?)
id like to get to read it when you get some done, if you dont mind :D

[WaveMaker04]

Thank you guys so much for the great ideas!

[Mermaid Annariea]

no problem :D

[Spindrift]

They could earn their souls by doing good deeds or something like that.