I've read through SoT a few times, and I'm doing it again currently. Right now, I've reached once more the visit by Sisters Grace, Elizabeth, and Verna to the Mud People's village, where the former two die by dacra after Richard refuses the Rada'Han.
But here's the thing. We learn later in Stone of Tears that Grace and Elizabeth were Sisters of the Dark. We also learn that there is a noticeable black flash when Sisters of the Dark are taken by the Keeper of the Underworld and tormented for eternity. So why didn't this happen? Wouldn't things have unfolded quite differently if Verna had known that her traveling companions were serving the Keeper?
Yes and this is why it DIDN'T happen. It's been said before in SoT but I will say it again. The Keeper is not stupid and is not going to reveal himself if there is a reason not to. If you think about it pretty much any other time it didn't really matter at all if he revealed himself.
Think about this as well if there had been that darkness then Verna would have reported it in the Journey Book and that would have raised really bad questions back at the Palace of the Prophets.
This is a very interesting and great observation; one I hadn't noticed nor ever considered before. I think it's an inconsistency flaw on the part of the author. Terry Goodkind probably wasn't certain that there would be more books following SoT, so when he introduced the convention of what's essentially a 'black-out' whenever a Sister of The Dark crosses the veil into the underworld, he probably forgot about Grace and Elizabeth; apparently his editors forgot/missed it too. Wow, imagine how much more interesting and richer the plot lines would've been if this detail was included in SoT... Good catch! :-)