Tiaral

From a role-playing perspective, I also lean towards this option. Actually, I have from the very beginning. But most people prefer a risky adventure.
— If I were sure they meant what they said, I would have done it that way, Aldric replied wearily. — But there are no guarantees that they won't continue to keep us on a leash for the rest of our lives. And that's if they even have a decent cure for this plague. That's why I think it's necessary to consider other options, including treatment for this plague. Pride is the least of my concerns in this situation.
— But our other plans have far more "buts" than simply following the Mist's instructions, — Rainhild objected. She understood perfectly that in this situation, Aldric was taking a much greater risk. If she had a chance to survive the journey to Tangion, due to her naturally strong immunity, the Jagendorf native could not boast anything similar.

Added 2 minutes later

I bet 10 gold pieces they wouldn't deceive us, or at least give us more powder to delay the effects?

The fact that we will live is very likely. But I wrote about the powder right away; they are unlikely to just give it to us like that. I mentioned it earlier. It seemed to me that we wanted to make the deception plan simply because it was the third option, even if it was doomed to fail.