Hey, just copy/pasted from this guide, hope it helps:
The Archimandrite's Riddle - Guess the most dangerous doorway to Xaos.
Requires: Be Aristo. Capture Linos & Horion safely. Have excellent Linos & Horion reputation.
Have Linos & Horion reach your camp by whatever method you prefer. The simplest is to send Zvad with orders to bring the strangers back to camp.
The achievement requires very friendly relations with them, so start on this as soon as you meet them. You must also make no reference to taking them hostage at any point - if your Father visits you the night before the Interrogation, you must choose:
“No, father. He’ll enjoy our hospitality, answer some questions…and in a day or two, he’ll be on his way.”
Then, when interrogating Linos, choose:
“What do you make of our rebellion?”
The answer is obvious.
Then type in “Compassion” (without the “”).
Law or Nature - Impress a noble with your grasp of philosophy.
Requires: Intellect 2. Capture Linos & Horion safely.
Have Linos & Horion reach your camp by whatever method you prefer. The simplest is to send Zvad with orders to bring the strangers back to camp. At the camp interrogate Horion.
If you are Aristo, DON’T choose any of the following options when asked your opinion on Harrowing or you’ll be unable to get the achievement:
I lower my voice to a prudent level. “Angels, I don’t want to bloody change their lot.”
“We’ll have a fairer system of Harrowing helots—that’s all.”
Otherwise, after asking your opinion on Harrowing, he’ll mention a Nyr philosopher called Aygul. Choose:
“I don’t know what’s nature and what’s law—and I’m not sure it matters.”
Then choose either of the two following options to unlock the achievement:
“Any law that runs counter to nature will fail eventually. That’s what ‘nature’ means.”
“Your philosopher meant that law can change, nature can’t. But everything changes. Even what we call nature.”
What is the issue you’re having ransoming them?