Neville's parents

[ksmith]

Are Frank and Alice Longbottom dead, or are they in some sort of asylum, never to be released? I'm wondering because in the movies I hear references that they suffered a fate worse than death. There's also the fact that Neville can't see the thestrals, but if he wasn't present when his parents died, assuming they died, then he wouldn't have been able to. I think.

Just wondering. I haven't read Order.