For crying out loud,
Urwen, it's not even been 10 days yet! If it's any consolation, I've been thinking about this, and if I had an inkling who it could be you can bet I'd have posted it.
I'm moderately sure it has to be a member of the Dor-lómin mafia, and reading "They refused the offer of the Dark one" my first thought was of Húrin rejecting Morgoth's offer of a captaincy in reward for betraying Turgon, but if "the dark one doesn't necessarily mean evil" that was obviously wrong - which leaves me rather clueless.
Anyway, belated thanks for standing in for me earlier. And it's 'cower', not 'cover'.
