These chapters seem to reenact a B movie about body snatchers in a fantasy setting and I love it. Plus, my favorite inside joke was done this update

Jaheira blocks the slash with her own sword, which breaks. That doppelganger really should've known better than to take the form of a female character in this book.
Maybe the iron poison is concentrated estrogen?

I feel a guy like Scar shouldn't be defeated by two Doppelgangers, at least not in an open fight. He is a seasoned mercenary CAPTAIN. I know that in reality holding yourself against two attackers is an extremely difficult thing. But this is a D&D novel. The medium where cheating dark elves with impossible fighting styles are able to kill dozens of Orcs. Realism should be the least of our concerns. Now if their weapons were poisoned or Doppel-Jaheira would've gone for a backstab I would have accepted this even without class features and in depth explanations. But the lack of an armor is certainly no reason.