I hope that you'll pardon a voice from the interested peanut gallery.

I found myself wondering whether the entrance of a "legendary beast" from territory "A" into territory "B" might rouse something that could have slept there for a long time, perhaps some kind of mythical beast that dwells beneath the fens?  Perhaps a race... hmm... something oily with tentacles and a penchant for fire?

Just a thought.  I'd build something myself but... I'm already overcommitted.