If the PCs decide to help the OTHER guy (they have no reason to know which one they're "supposed" to be helping), the NPC will also die.
Odds the PCs will now kill him without further ado? Pretty high in my experience.
(I am not making this up.)
This is the first time the PCs will be able to learn this, so...
thealexandrian.net/wordpress/4416…
1. Elturel was destroyed
2. Elturel was destroyed by devils
3. High Observer Kreeg is still alive!
4. Kreeg is responsible!
5. Elturel was actually taken to the Nine Hells
And everything else is equally dysfunctional.
...except the person who tells them to go to Candlekeep and do that literally tells them that's what's in the box.
What bothers me is that there doesn't seem to BE a scheme.
If you're going to put your players on a railroad, at least do them the courtesy of making sure the engine is in good repair.
thealexandrian.net/wordpress/3690…
(Actual quote.)
(Not an actual quote.)
(But that is what the adventure tells the GM to do.)