A tall ship and a star to steer her by (starwreck) wrote in valarnet,
Bones helped innoculate a planet against a virus years ago, but after he left another plague came and they blamed him. Bones thought that maybe it was his fault, that he'd accidentally brought a pathogen to them without realizing it.
We discovered that Vulcans were immune, so beamed Spock down to the plague planet after traveling through a space aurora. We discovered a survivor, who agreed to testify for Bones. But when we took him to the ship he started exhibiting symptoms.
We ended up breaking Bones out of prison so he could devise a cure, and discovered that the space aurora had caused the disease. It had passed by the planet not long after he'd left it.