Bones is a Mer

[judybrowneyes54]

I'm looking for a fic where Bones is a Mer but no one on the ship knows because he hates water and his Mer self. He gets sick or he's already sick when he and Jim go on away mission to a water planet. He can be cured but only if he can shift to a Mer in the water. If I remember correctly this fic is a pre STID fic, so it's an older one.

I hope someone remembers this one, I'd love to reread it. Thanks in advance.