In the episode Sub Rosa we learn that Ronan was a “boyfriend” of the Howard women “for generations.” He was an anaphasic life form that needed an organic host to live (or something like that). Bev said something to the effect that at some point Ronan must have realized that the Howard women had the right biochemical makeup that Ronan needed to live. If you recall from the episode, Ronan killed a friend of Bev’s Nana. I believe they said that it was anaphasic energy that killed him. After the crew figured this out, they realized that there was a large reading of anaphasic energy coming from Nana’s grave. In fact, it was her body that was letting off this energy. They said that she died from natural causes, but yet they didn’t realize that she had a large amount of anaphasic energy until the end of the episode. Do you think that Ronan’s relationship with Nana is what led to her death? I can’t figure it out, especially since at the end of the episode Bev tells Deanna she’s sad and that despite what Ronan did, he made her Nana very happy.